diff --git a/ui-electrobun/src/mainview/AgentPane.svelte b/ui-electrobun/src/mainview/AgentPane.svelte
index aaeba99..5a6bf47 100644
--- a/ui-electrobun/src/mainview/AgentPane.svelte
+++ b/ui-electrobun/src/mainview/AgentPane.svelte
@@ -31,10 +31,12 @@
   }: Props = $props();
 
   let scrollEl: HTMLDivElement;
+  // These need $state because Svelte 5 template bindings require reactive
+  // declarations. Rule 58 exception: component-scoped UI state that drives
+  // template output but has no cross-component readers.
   let promptText = $state("");
   let expandedTools = $state<Set<string>>(new Set());
 
-  // Drag-resize state
   let agentPaneEl: HTMLDivElement;
   let isDragging = $state(false);
 
diff --git a/ui-electrobun/src/mainview/CommsTab.svelte b/ui-electrobun/src/mainview/CommsTab.svelte
index 069437f..eecaea1 100644
--- a/ui-electrobun/src/mainview/CommsTab.svelte
+++ b/ui-electrobun/src/mainview/CommsTab.svelte
@@ -1,82 +1,29 @@
 <script lang="ts">
   import { appRpc } from './rpc.ts';
-
-  // ── Types ────────────────────────────────────────────────────────────
-
-  interface Channel {
-    id: string;
-    name: string;
-    groupId: string;
-    createdBy: string;
-    memberCount: number;
-    createdAt: string;
-  }
-
-  interface ChannelMessage {
-    id: string;
-    channelId: string;
-    fromAgent: string;
-    content: string;
-    createdAt: string;
-    senderName: string;
-    senderRole: string;
-  }
-
-  interface Agent {
-    id: string;
-    name: string;
-    role: string;
-    groupId: string;
-    tier: number;
-    status: string;
-    unreadCount: number;
-  }
-
-  interface DM {
-    id: string;
-    fromAgent: string;
-    toAgent: string;
-    content: string;
-    read: boolean;
-    createdAt: string;
-    senderName: string | null;
-    senderRole: string | null;
-  }
+  import { appState } from './app-state.svelte.ts';
 
   interface Props {
     groupId: string;
+    projectId: string;
     /** Agent ID for this project's perspective (defaults to 'admin'). */
     agentId?: string;
   }
 
-  let { groupId, agentId = 'admin' }: Props = $props();
+  let { groupId, projectId, agentId = 'admin' }: Props = $props();
 
-  // ── State ────────────────────────────────────────────────────────────
-
-  type TabMode = 'channels' | 'dms';
-  let mode = $state<TabMode>('channels');
-
-  let channels = $state<Channel[]>([]);
-  let agents = $state<Agent[]>([]);
-  let activeChannelId = $state<string | null>(null);
-  let activeDmAgentId = $state<string | null>(null);
-  let channelMessages = $state<ChannelMessage[]>([]);
-  let dmMessages = $state<DM[]>([]);
-  let input = $state('');
-  let loading = $state(false);
-  // Feature 7: Channel member list
-  let channelMembers = $state<Array<{ agentId: string; name: string; role: string }>>([]);
-  let showMembers = $state(false);
+  // Read comms state from project state tree
+  function getComms() { return appState.project.getState(projectId).comms; }
 
   // ── Data fetching ────────────────────────────────────────────────────
 
   async function loadChannels() {
     try {
       const res = await appRpc.request['btmsg.listChannels']({ groupId });
-      channels = res.channels;
-      if (channels.length > 0 && !activeChannelId) {
-        activeChannelId = channels[0].id;
-        await loadChannelMessages(channels[0].id);
+      appState.project.comms.setState(projectId, 'channels', res.channels);
+      const c = getComms();
+      if (c.channels.length > 0 && !c.activeChannelId) {
+        appState.project.comms.setState(projectId, 'activeChannelId', c.channels[0].id);
+        await loadChannelMessages(c.channels[0].id);
       }
     } catch (err) {
       console.error('[CommsTab] loadChannels:', err);
@@ -86,7 +33,8 @@
   async function loadAgents() {
     try {
       const res = await appRpc.request['btmsg.getAgents']({ groupId });
-      agents = res.agents.filter((a: Agent) => a.id !== agentId);
+      appState.project.comms.setState(projectId, 'agents',
+        res.agents.filter((a: { id: string }) => a.id !== agentId));
     } catch (err) {
       console.error('[CommsTab] loadAgents:', err);
     }
@@ -94,70 +42,69 @@
 
   async function loadChannelMessages(channelId: string) {
     try {
-      loading = true;
+      appState.project.comms.setState(projectId, 'loading', true);
       const res = await appRpc.request['btmsg.getChannelMessages']({
         channelId, limit: 100,
       });
-      channelMessages = res.messages;
+      appState.project.comms.setState(projectId, 'channelMessages', res.messages);
     } catch (err) {
       console.error('[CommsTab] loadChannelMessages:', err);
     } finally {
-      loading = false;
+      appState.project.comms.setState(projectId, 'loading', false);
     }
   }
 
   async function loadDmMessages(otherId: string) {
     try {
-      loading = true;
+      appState.project.comms.setState(projectId, 'loading', true);
       const res = await appRpc.request['btmsg.listMessages']({
         agentId, otherId, limit: 50,
       });
-      dmMessages = res.messages;
+      appState.project.comms.setState(projectId, 'dmMessages', res.messages);
     } catch (err) {
       console.error('[CommsTab] loadDmMessages:', err);
     } finally {
-      loading = false;
+      appState.project.comms.setState(projectId, 'loading', false);
     }
   }
 
   function selectChannel(id: string) {
-    activeChannelId = id;
-    showMembers = false;
+    appState.project.comms.setMulti(projectId, { activeChannelId: id, showMembers: false });
     loadChannelMessages(id);
     loadChannelMembers(id);
   }
 
-  // Feature 7: Load channel members
   async function loadChannelMembers(channelId: string) {
     try {
       const res = await appRpc.request['btmsg.getChannelMembers']({ channelId });
-      channelMembers = res.members;
+      appState.project.comms.setState(projectId, 'channelMembers', res.members);
     } catch (err) {
       console.error('[CommsTab] loadChannelMembers:', err);
     }
   }
 
   function selectDm(otherId: string) {
-    activeDmAgentId = otherId;
+    appState.project.comms.setState(projectId, 'activeDmAgentId', otherId);
     loadDmMessages(otherId);
   }
 
   async function sendMessage() {
-    const text = input.trim();
+    const c = getComms();
+    const text = c.input.trim();
     if (!text) return;
-    input = '';
+    appState.project.comms.setState(projectId, 'input', '');
 
     try {
-      if (mode === 'channels' && activeChannelId) {
+      if (c.mode === 'channels' && c.activeChannelId) {
         await appRpc.request['btmsg.sendChannelMessage']({
-          channelId: activeChannelId, fromAgent: agentId, content: text,
+          channelId: c.activeChannelId, fromAgent: agentId, content: text,
         });
-        await loadChannelMessages(activeChannelId);
-      } else if (mode === 'dms' && activeDmAgentId) {
+        await loadChannelMessages(c.activeChannelId);
+      } else if (c.mode === 'dms' && c.activeDmAgentId) {
         await appRpc.request['btmsg.sendMessage']({
-          fromAgent: agentId, toAgent: activeDmAgentId, content: text,
+          fromAgent: agentId, toAgent: c.activeDmAgentId, content: text,
         });
-        await loadDmMessages(activeDmAgentId);
+        await loadDmMessages(c.activeDmAgentId);
       }
     } catch (err) {
       console.error('[CommsTab] sendMessage:', err);
@@ -175,28 +122,28 @@
 
   let pollTimer: ReturnType<typeof setInterval> | null = null;
 
-  // Feature 4: Listen for push events
   function onNewMessage(payload: { groupId: string; channelId?: string }) {
-    if (mode === 'channels' && activeChannelId) {
-      if (!payload.channelId || payload.channelId === activeChannelId) {
-        loadChannelMessages(activeChannelId);
+    const c = getComms();
+    if (c.mode === 'channels' && c.activeChannelId) {
+      if (!payload.channelId || payload.channelId === c.activeChannelId) {
+        loadChannelMessages(c.activeChannelId);
       }
-    } else if (mode === 'dms' && activeDmAgentId) {
-      loadDmMessages(activeDmAgentId);
+    } else if (c.mode === 'dms' && c.activeDmAgentId) {
+      loadDmMessages(c.activeDmAgentId);
     }
   }
 
-  // Use onMount instead of $effect — loadChannels/loadAgents write to $state
   import { onMount } from 'svelte';
   onMount(() => {
     loadChannels();
     loadAgents();
     appRpc.addMessageListener('btmsg.newMessage', onNewMessage);
     pollTimer = setInterval(() => {
-      if (mode === 'channels' && activeChannelId) {
-        loadChannelMessages(activeChannelId);
-      } else if (mode === 'dms' && activeDmAgentId) {
-        loadDmMessages(activeDmAgentId);
+      const c = getComms();
+      if (c.mode === 'channels' && c.activeChannelId) {
+        loadChannelMessages(c.activeChannelId);
+      } else if (c.mode === 'dms' && c.activeDmAgentId) {
+        loadDmMessages(c.activeDmAgentId);
       }
     }, 30000);
     return () => {
@@ -211,38 +158,38 @@
   <div class="comms-mode-bar">
     <button
       class="mode-btn"
-      class:active={mode === 'channels'}
-      onclick={() => { mode = 'channels'; }}
+      class:active={getComms().mode === 'channels'}
+      onclick={() => { appState.project.comms.setState(projectId, 'mode', 'channels'); }}
     >Channels</button>
     <button
       class="mode-btn"
-      class:active={mode === 'dms'}
-      onclick={() => { mode = 'dms'; loadAgents(); }}
+      class:active={getComms().mode === 'dms'}
+      onclick={() => { appState.project.comms.setState(projectId, 'mode', 'dms'); loadAgents(); }}
     >DMs</button>
   </div>
 
   <div class="comms-body">
     <!-- Sidebar: channel list or agent list -->
     <div class="comms-sidebar">
-      {#if mode === 'channels'}
-        {#each channels as ch}
+      {#if getComms().mode === 'channels'}
+        {#each getComms().channels as ch}
           <button
             class="sidebar-item"
-            class:active={activeChannelId === ch.id}
+            class:active={getComms().activeChannelId === ch.id}
             onclick={() => selectChannel(ch.id)}
           >
             <span class="ch-hash">#</span>
             <span class="ch-name">{ch.name}</span>
           </button>
         {/each}
-        {#if channels.length === 0}
+        {#if getComms().channels.length === 0}
           <div class="sidebar-empty">No channels</div>
         {/if}
       {:else}
-        {#each agents as ag}
+        {#each getComms().agents as ag}
           <button
             class="sidebar-item"
-            class:active={activeDmAgentId === ag.id}
+            class:active={getComms().activeDmAgentId === ag.id}
             onclick={() => selectDm(ag.id)}
           >
             <span class="agent-dot {ag.status}"></span>
@@ -253,7 +200,7 @@
             {/if}
           </button>
         {/each}
-        {#if agents.length === 0}
+        {#if getComms().agents.length === 0}
           <div class="sidebar-empty">No agents</div>
         {/if}
       {/if}
@@ -261,11 +208,11 @@
 
     <!-- Message area -->
     <div class="comms-messages">
-      {#if loading}
+      {#if getComms().loading}
         <div class="msg-loading">Loading...</div>
-      {:else if mode === 'channels'}
+      {:else if getComms().mode === 'channels'}
         <div class="msg-list">
-          {#each channelMessages as msg}
+          {#each getComms().channelMessages as msg}
             <div class="msg-row">
               <span class="msg-sender">{msg.senderName}</span>
               <span class="msg-role">{msg.senderRole}</span>
@@ -273,36 +220,36 @@
               <div class="msg-content">{msg.content}</div>
             </div>
           {/each}
-          {#if channelMessages.length === 0}
+          {#if getComms().channelMessages.length === 0}
             <div class="msg-empty">No messages in this channel</div>
           {/if}
         </div>
       {:else}
         <div class="msg-list">
-          {#each dmMessages as msg}
+          {#each getComms().dmMessages as msg}
             <div class="msg-row" class:msg-mine={msg.fromAgent === agentId}>
               <span class="msg-sender">{msg.senderName ?? msg.fromAgent}</span>
               <span class="msg-time">{msg.createdAt.slice(11, 16)}</span>
               <div class="msg-content">{msg.content}</div>
             </div>
           {/each}
-          {#if dmMessages.length === 0 && activeDmAgentId}
+          {#if getComms().dmMessages.length === 0 && getComms().activeDmAgentId}
             <div class="msg-empty">No messages yet</div>
           {/if}
-          {#if !activeDmAgentId}
+          {#if !getComms().activeDmAgentId}
             <div class="msg-empty">Select an agent to message</div>
           {/if}
         </div>
       {/if}
 
       <!-- Feature 7: Channel member list toggle -->
-      {#if mode === 'channels' && activeChannelId}
-        <button class="members-toggle" onclick={() => showMembers = !showMembers}>
-          Members ({channelMembers.length})
+      {#if getComms().mode === 'channels' && getComms().activeChannelId}
+        <button class="members-toggle" onclick={() => appState.project.comms.setState(projectId, 'showMembers', !getComms().showMembers)}>
+          Members ({getComms().channelMembers.length})
         </button>
-        {#if showMembers}
+        {#if getComms().showMembers}
           <div class="members-list">
-            {#each channelMembers as m}
+            {#each getComms().channelMembers as m}
               <span class="member-chip">{m.name} <span class="member-role">{m.role}</span></span>
             {/each}
           </div>
@@ -314,11 +261,12 @@
         <input
           class="msg-input"
           type="text"
-          placeholder={mode === 'channels' ? 'Message channel...' : 'Send DM...'}
-          bind:value={input}
+          placeholder={getComms().mode === 'channels' ? 'Message channel...' : 'Send DM...'}
+          value={getComms().input}
+          oninput={(e) => appState.project.comms.setState(projectId, 'input', (e.target as HTMLInputElement).value)}
           onkeydown={handleKeydown}
         />
-        <button class="msg-send-btn" onclick={sendMessage} disabled={!input.trim()}>
+        <button class="msg-send-btn" onclick={sendMessage} disabled={!getComms().input.trim()}>
           Send
         </button>
       </div>
diff --git a/ui-electrobun/src/mainview/FileBrowser.svelte b/ui-electrobun/src/mainview/FileBrowser.svelte
index cc0c2d1..6316be4 100644
--- a/ui-electrobun/src/mainview/FileBrowser.svelte
+++ b/ui-electrobun/src/mainview/FileBrowser.svelte
@@ -3,38 +3,17 @@
   import CodeEditor from './CodeEditor.svelte';
   import PdfViewer from './PdfViewer.svelte';
   import CsvTable from './CsvTable.svelte';
+  import { appState } from './app-state.svelte.ts';
 
   interface Props {
     cwd: string;
+    projectId: string;
   }
 
-  let { cwd }: Props = $props();
+  let { cwd, projectId }: Props = $props();
 
-  interface DirEntry {
-    name: string;
-    type: 'file' | 'dir';
-    size: number;
-  }
-
-  // Tree state: track loaded children and open/closed per path
-  let childrenCache = $state<Map<string, DirEntry[]>>(new Map());
-  let openDirs = $state<Set<string>>(new Set());
-  let loadingDirs = $state<Set<string>>(new Set());
-  let selectedFile = $state<string | null>(null);
-
-  // File viewer state
-  let fileContent = $state<string | null>(null);
-  let fileEncoding = $state<'utf8' | 'base64'>('utf8');
-  let fileSize = $state(0);
-  let fileError = $state<string | null>(null);
-  let fileLoading = $state(false);
-  let isDirty = $state(false);
-  let editorContent = $state('');
-  // Fix #6: Request token to discard stale file load responses
-  let fileRequestToken = 0;
-  // Feature 2: Track mtime at read time for conflict detection
-  let readMtimeMs = $state(0);
-  let showConflictDialog = $state(false);
+  // Read file state from project state tree
+  function getFiles() { return appState.project.getState(projectId).files; }
 
   // Extension-based type detection
   const CODE_EXTS = new Set([
@@ -81,117 +60,124 @@
     return map[ext] ?? 'text';
   }
 
-  let selectedType = $derived<FileType>(selectedFile ? detectFileType(selectedFile) : 'text');
-  let selectedName = $derived(selectedFile ? selectedFile.split('/').pop() ?? '' : '');
+  function getSelectedType(): FileType {
+    const f = getFiles().selectedFile;
+    return f ? detectFileType(f) : 'text';
+  }
+  function getSelectedName(): string {
+    const f = getFiles().selectedFile;
+    return f ? f.split('/').pop() ?? '' : '';
+  }
 
   /** Load directory entries via RPC. */
   async function loadDir(dirPath: string) {
-    if (childrenCache.has(dirPath)) return;
-    const key = dirPath;
-    loadingDirs = new Set([...loadingDirs, key]);
+    const f = getFiles();
+    if (f.childrenCache.has(dirPath)) return;
+    f.loadingDirs.add(dirPath);
+    appState.project.files.setState(projectId, 'loadingDirs', new Set(f.loadingDirs));
     try {
       const result = await appRpc.request["files.list"]({ path: dirPath });
       if (result.error) {
         console.error(`[files.list] ${dirPath}: ${result.error}`);
         return;
       }
-      const next = new Map(childrenCache);
-      next.set(dirPath, result.entries);
-      childrenCache = next;
+      f.childrenCache.set(dirPath, result.entries);
+      appState.project.files.setState(projectId, 'childrenCache', new Map(f.childrenCache));
     } catch (err) {
       console.error('[files.list]', err);
     } finally {
-      const s = new Set(loadingDirs);
-      s.delete(key);
-      loadingDirs = s;
+      f.loadingDirs.delete(dirPath);
+      appState.project.files.setState(projectId, 'loadingDirs', new Set(f.loadingDirs));
     }
   }
 
   /** Toggle a directory open/closed. Lazy-loads on first open. */
   async function toggleDir(dirPath: string) {
-    const s = new Set(openDirs);
+    const f = getFiles();
+    const s = new Set(f.openDirs);
     if (s.has(dirPath)) {
       s.delete(dirPath);
-      openDirs = s;
     } else {
       s.add(dirPath);
-      openDirs = s;
-      await loadDir(dirPath);
     }
+    appState.project.files.setState(projectId, 'openDirs', s);
+    if (s.has(dirPath)) await loadDir(dirPath);
   }
 
   /** Select and load a file. Fix #6: uses request token to discard stale responses. */
   async function selectFile(filePath: string) {
-    if (selectedFile === filePath) return;
-    selectedFile = filePath;
-    isDirty = false;
-    fileContent = null;
-    fileError = null;
-    fileLoading = true;
-    const token = ++fileRequestToken;
-
+    const f = getFiles();
+    if (f.selectedFile === filePath) return;
+    appState.project.files.setMulti(projectId, {
+      selectedFile: filePath, isDirty: false, fileContent: null,
+      fileError: null, fileLoading: true,
+    });
+    const token = appState.project.files.nextRequestToken(projectId);
     const type = detectFileType(filePath);
 
-    // PDF uses its own loader via PdfViewer
     if (type === 'pdf') {
-      fileLoading = false;
+      appState.project.files.setState(projectId, 'fileLoading', false);
       return;
     }
 
-    // Images: read as base64 for display
     if (type === 'image') {
       try {
         const result = await appRpc.request["files.read"]({ path: filePath });
-        if (token !== fileRequestToken) return;
+        if (token !== appState.project.files.getRequestToken(projectId)) return;
         if (result.error) {
-          fileError = result.error;
+          appState.project.files.setState(projectId, 'fileError', result.error);
           return;
         }
-        fileContent = result.content ?? '';
-        fileEncoding = result.encoding;
-        fileSize = result.size;
+        appState.project.files.setMulti(projectId, {
+          fileContent: result.content ?? '', fileEncoding: result.encoding, fileSize: result.size,
+        });
       } catch (err) {
-        if (token !== fileRequestToken) return;
-        fileError = err instanceof Error ? err.message : String(err);
+        if (token !== appState.project.files.getRequestToken(projectId)) return;
+        appState.project.files.setState(projectId, 'fileError', err instanceof Error ? err.message : String(err));
       } finally {
-        if (token === fileRequestToken) fileLoading = false;
+        if (token === appState.project.files.getRequestToken(projectId)) {
+          appState.project.files.setState(projectId, 'fileLoading', false);
+        }
       }
       return;
     }
 
     try {
       const result = await appRpc.request["files.read"]({ path: filePath });
-      if (token !== fileRequestToken) return;
+      if (token !== appState.project.files.getRequestToken(projectId)) return;
       if (result.error) {
-        fileError = result.error;
+        appState.project.files.setState(projectId, 'fileError', result.error);
         return;
       }
-      fileContent = result.content ?? '';
-      fileEncoding = result.encoding;
-      fileSize = result.size;
-      editorContent = fileContent;
-      // Feature 2: Record mtime at read time
+      appState.project.files.setMulti(projectId, {
+        fileContent: result.content ?? '', fileEncoding: result.encoding,
+        fileSize: result.size, editorContent: result.content ?? '',
+      });
       try {
         const stat = await appRpc.request["files.stat"]({ path: filePath });
-        if (token === fileRequestToken && !stat.error) readMtimeMs = stat.mtimeMs;
+        if (token === appState.project.files.getRequestToken(projectId) && !stat.error) {
+          appState.project.files.setState(projectId, 'readMtimeMs', stat.mtimeMs);
+        }
       } catch { /* non-critical */ }
     } catch (err) {
-      if (token !== fileRequestToken) return;
-      fileError = err instanceof Error ? err.message : String(err);
+      if (token !== appState.project.files.getRequestToken(projectId)) return;
+      appState.project.files.setState(projectId, 'fileError', err instanceof Error ? err.message : String(err));
     } finally {
-      if (token === fileRequestToken) fileLoading = false;
+      if (token === appState.project.files.getRequestToken(projectId)) {
+        appState.project.files.setState(projectId, 'fileLoading', false);
+      }
     }
   }
 
   /** Save current file. Feature 2: Check mtime before write for conflict detection. */
   async function saveFile() {
-    if (!selectedFile || !isDirty) return;
+    const f = getFiles();
+    if (!f.selectedFile || !f.isDirty) return;
     try {
-      // Feature 2: Check if file was modified externally since we read it
-      if (readMtimeMs > 0) {
-        const stat = await appRpc.request["files.stat"]({ path: selectedFile });
-        if (!stat.error && stat.mtimeMs > readMtimeMs) {
-          showConflictDialog = true;
+      if (f.readMtimeMs > 0) {
+        const stat = await appRpc.request["files.stat"]({ path: f.selectedFile });
+        if (!stat.error && stat.mtimeMs > f.readMtimeMs) {
+          appState.project.files.setState(projectId, 'showConflictDialog', true);
           return;
         }
       }
@@ -203,19 +189,18 @@
 
   /** Force-save, bypassing conflict check. */
   async function doSave() {
-    if (!selectedFile) return;
+    const f = getFiles();
+    if (!f.selectedFile) return;
     try {
       const result = await appRpc.request["files.write"]({
-        path: selectedFile,
-        content: editorContent,
+        path: f.selectedFile, content: f.editorContent,
       });
       if (result.ok) {
-        isDirty = false;
-        fileContent = editorContent;
-        showConflictDialog = false;
-        // Update mtime after successful save
-        const stat = await appRpc.request["files.stat"]({ path: selectedFile });
-        if (!stat.error) readMtimeMs = stat.mtimeMs;
+        appState.project.files.setMulti(projectId, {
+          isDirty: false, fileContent: f.editorContent, showConflictDialog: false,
+        });
+        const stat = await appRpc.request["files.stat"]({ path: f.selectedFile });
+        if (!stat.error) appState.project.files.setState(projectId, 'readMtimeMs', stat.mtimeMs);
       } else if (result.error) {
         console.error('[files.write]', result.error);
       }
@@ -226,18 +211,21 @@
 
   /** Reload file from disk (discard local changes). */
   async function reloadFile() {
-    showConflictDialog = false;
-    if (selectedFile) {
-      isDirty = false;
-      const saved = selectedFile;
-      selectedFile = null;
+    appState.project.files.setState(projectId, 'showConflictDialog', false);
+    const f = getFiles();
+    if (f.selectedFile) {
+      appState.project.files.setState(projectId, 'isDirty', false);
+      const saved = f.selectedFile;
+      appState.project.files.setState(projectId, 'selectedFile', null);
       await selectFile(saved);
     }
   }
 
   function onEditorChange(newContent: string) {
-    editorContent = newContent;
-    isDirty = newContent !== fileContent;
+    const f = getFiles();
+    appState.project.files.setMulti(projectId, {
+      editorContent: newContent, isDirty: newContent !== f.fileContent,
+    });
   }
 
   function fileIcon(name: string): string {
@@ -264,12 +252,11 @@
   }
 
   // Load root directory on mount — use onMount, NOT $effect
-  // $effect reads openDirs (via new Set(openDirs)) and writes to it → infinite loop
   import { onMount } from 'svelte';
   onMount(() => {
     if (cwd) {
       loadDir(cwd);
-      openDirs = new Set([cwd]);
+      appState.project.files.setState(projectId, 'openDirs', new Set([cwd]));
     }
   });
 </script>
@@ -278,41 +265,41 @@
   <!-- Tree panel -->
   <div class="fb-tree">
     {#snippet renderEntries(dirPath: string, depth: number)}
-      {#if childrenCache.has(dirPath)}
-        {#each childrenCache.get(dirPath) ?? [] as entry}
+      {#if getFiles().childrenCache.has(dirPath)}
+        {#each getFiles().childrenCache.get(dirPath) ?? [] as entry}
           {@const fullPath = `${dirPath}/${entry.name}`}
           {#if entry.type === 'dir'}
             <button
               class="fb-row fb-dir"
               style:padding-left="{0.5 + depth * 0.875}rem"
               onclick={() => toggleDir(fullPath)}
-              aria-expanded={openDirs.has(fullPath)}
+              aria-expanded={getFiles().openDirs.has(fullPath)}
             >
-              <span class="fb-chevron" class:open={openDirs.has(fullPath)}>
-                {#if loadingDirs.has(fullPath)}...{:else}>{/if}
+              <span class="fb-chevron" class:open={getFiles().openDirs.has(fullPath)}>
+                {#if getFiles().loadingDirs.has(fullPath)}...{:else}>{/if}
               </span>
               <span class="fb-name">{entry.name}</span>
             </button>
-            {#if openDirs.has(fullPath)}
+            {#if getFiles().openDirs.has(fullPath)}
               {@render renderEntries(fullPath, depth + 1)}
             {/if}
           {:else}
             <button
               class="fb-row fb-file"
-              class:selected={selectedFile === fullPath}
+              class:selected={getFiles().selectedFile === fullPath}
               style:padding-left="{0.5 + depth * 0.875}rem"
               onclick={() => selectFile(fullPath)}
               title={`${entry.name} (${formatSize(entry.size)})`}
             >
               <span class="fb-icon file-type">{fileIcon(entry.name)}</span>
               <span class="fb-name">{entry.name}</span>
-              {#if selectedFile === fullPath && isDirty}
+              {#if getFiles().selectedFile === fullPath && getFiles().isDirty}
                 <span class="dirty-dot" title="Unsaved changes"></span>
               {/if}
             </button>
           {/if}
         {/each}
-      {:else if loadingDirs.has(dirPath)}
+      {:else if getFiles().loadingDirs.has(dirPath)}
         <div class="fb-loading" style:padding-left="{0.5 + depth * 0.875}rem">Loading...</div>
       {/if}
     {/snippet}
@@ -321,7 +308,7 @@
   </div>
 
   <!-- Feature 2: Conflict dialog -->
-  {#if showConflictDialog}
+  {#if getFiles().showConflictDialog}
     <div class="conflict-overlay">
       <div class="conflict-dialog">
         <p class="conflict-title">File modified externally</p>
@@ -329,7 +316,7 @@
         <div class="conflict-actions">
           <button class="conflict-btn overwrite" onclick={doSave}>Overwrite</button>
           <button class="conflict-btn reload" onclick={reloadFile}>Reload</button>
-          <button class="conflict-btn cancel" onclick={() => showConflictDialog = false}>Cancel</button>
+          <button class="conflict-btn cancel" onclick={() => appState.project.files.setState(projectId, 'showConflictDialog', false)}>Cancel</button>
         </div>
       </div>
     </div>
@@ -337,53 +324,53 @@
 
   <!-- Viewer panel -->
   <div class="fb-viewer">
-    {#if !selectedFile}
+    {#if !getFiles().selectedFile}
       <div class="fb-empty">Select a file to view</div>
-    {:else if fileLoading}
+    {:else if getFiles().fileLoading}
       <div class="fb-empty">Loading...</div>
-    {:else if fileError}
-      <div class="fb-error">{fileError}</div>
-    {:else if selectedType === 'pdf'}
-      <PdfViewer filePath={selectedFile} />
-    {:else if selectedType === 'csv' && fileContent != null}
-      <CsvTable content={fileContent} filename={selectedName} />
-    {:else if selectedType === 'image' && fileContent}
-      {@const ext = getExt(selectedName)}
+    {:else if getFiles().fileError}
+      <div class="fb-error">{getFiles().fileError}</div>
+    {:else if getSelectedType() === 'pdf'}
+      <PdfViewer filePath={getFiles().selectedFile ?? ''} />
+    {:else if getSelectedType() === 'csv' && getFiles().fileContent != null}
+      <CsvTable content={getFiles().fileContent ?? ''} filename={getSelectedName()} />
+    {:else if getSelectedType() === 'image' && getFiles().fileContent}
+      {@const ext = getExt(getSelectedName())}
       {@const mime = ext === 'svg' ? 'image/svg+xml' : ext === 'png' ? 'image/png' : ext === 'gif' ? 'image/gif' : ext === 'webp' ? 'image/webp' : 'image/jpeg'}
       <div class="fb-image-wrap">
-        <div class="fb-image-label">{selectedName} ({formatSize(fileSize)})</div>
+        <div class="fb-image-label">{getSelectedName()} ({formatSize(getFiles().fileSize)})</div>
         <img
           class="fb-image"
-          src="data:{mime};base64,{fileEncoding === 'base64' ? fileContent : btoa(fileContent)}"
-          alt={selectedName}
+          src="data:{mime};base64,{getFiles().fileEncoding === 'base64' ? getFiles().fileContent : btoa(getFiles().fileContent ?? '')}"
+          alt={getSelectedName()}
         />
       </div>
-    {:else if selectedType === 'code' && fileContent != null}
+    {:else if getSelectedType() === 'code' && getFiles().fileContent != null}
       <div class="fb-editor-header">
-        <span class="fb-editor-path" title={selectedFile}>
-          {selectedName}
-          {#if isDirty}<span class="dirty-indicator"> (modified)</span>{/if}
+        <span class="fb-editor-path" title={getFiles().selectedFile ?? ''}>
+          {getSelectedName()}
+          {#if getFiles().isDirty}<span class="dirty-indicator"> (modified)</span>{/if}
         </span>
-        <span class="fb-editor-size">{formatSize(fileSize)}</span>
+        <span class="fb-editor-size">{formatSize(getFiles().fileSize)}</span>
       </div>
       <CodeEditor
-        content={fileContent}
-        lang={extToLang(selectedFile)}
+        content={getFiles().fileContent ?? ''}
+        lang={extToLang(getFiles().selectedFile ?? '')}
         onsave={saveFile}
         onchange={onEditorChange}
         onblur={saveFile}
       />
-    {:else if fileContent != null}
+    {:else if getFiles().fileContent != null}
       <!-- Raw text fallback -->
       <div class="fb-editor-header">
-        <span class="fb-editor-path" title={selectedFile}>
-          {selectedName}
-          {#if isDirty}<span class="dirty-indicator"> (modified)</span>{/if}
+        <span class="fb-editor-path" title={getFiles().selectedFile ?? ''}>
+          {getSelectedName()}
+          {#if getFiles().isDirty}<span class="dirty-indicator"> (modified)</span>{/if}
         </span>
-        <span class="fb-editor-size">{formatSize(fileSize)}</span>
+        <span class="fb-editor-size">{formatSize(getFiles().fileSize)}</span>
       </div>
       <CodeEditor
-        content={fileContent}
+        content={getFiles().fileContent ?? ''}
         lang="text"
         onsave={saveFile}
         onchange={onEditorChange}
diff --git a/ui-electrobun/src/mainview/ProjectCard.svelte b/ui-electrobun/src/mainview/ProjectCard.svelte
index 6c5caac..40dd025 100644
--- a/ui-electrobun/src/mainview/ProjectCard.svelte
+++ b/ui-electrobun/src/mainview/ProjectCard.svelte
@@ -8,15 +8,8 @@
   import DocsTab from './DocsTab.svelte';
   import SshTab from './SshTab.svelte';
   import StatusDot from './ui/StatusDot.svelte';
-  import {
-    startAgent, stopAgent, sendPrompt, getSession, hasSession,
-    loadLastSession,
-    type AgentStatus, type AgentMessage,
-  } from './agent-store.svelte.ts';
-  import {
-    getActiveTab, setActiveTab, isTabActivated,
-    ALL_TABS, type ProjectTab,
-  } from './project-tabs-store.svelte.ts';
+  import { appState, type AgentStatus, type AgentMessage, type ProjectTab } from './app-state.svelte.ts';
+  import { ALL_TABS } from './project-tabs-store.svelte.ts';
 
   interface Props {
     id: string;
@@ -61,9 +54,7 @@
 
   // ── Agent session (reactive from store) ──────────────────────────
   const EMPTY_MESSAGES: AgentMessage[] = [];
-  // ALL agent session state as plain getter functions — NO $derived.
-  // $derived + store getters that return new refs = infinite loops in Svelte 5.
-  function getAgentSession() { return getSession(id); }
+  function getAgentSession() { return appState.agent.getSession(id); }
   function getAgentStatus(): AgentStatus { return getAgentSession()?.status ?? 'idle'; }
   function getAgentMessages(): AgentMessage[] { return getAgentSession()?.messages ?? []; }
   function getAgentCost(): number { return getAgentSession()?.costUsd ?? 0; }
@@ -107,7 +98,7 @@
     return getAgentMessages().length > 0 ? getAgentMessages() : EMPTY_MESSAGES;
   }
 
-  // ── Clone dialog state ──────────────────────────────────────────
+  // ── Clone dialog state (needs $state for template bindings) ─────
   let showCloneDialog = $state(false);
   let cloneBranchName = $state('');
   let cloneError = $state('');
@@ -129,33 +120,31 @@
     showCloneDialog = false;
   }
 
-  // Derived from project-tabs-store for reactive reads
-  function getCurrentTab() { return getActiveTab(id); }
+  // Tab state from project state tree
+  function getCurrentTab() { return appState.project.tab.getActiveTab(id); }
 
   // ── Load last session on mount (once, not reactive) ─────────────────
   import { onMount } from 'svelte';
-  onMount(() => { loadLastSession(id); });
+  onMount(() => { appState.agent.loadLastSession(id); });
 
   function setTab(tab: ProjectTab) {
-    setActiveTab(id, tab);
+    appState.project.tab.setActiveTab(id, tab);
   }
 
   function handleSend(text: string) {
-    if (hasSession(id)) {
-      // Session exists — send follow-up prompt
-      sendPrompt(id, text).catch((err) => {
+    if (appState.agent.hasSession(id)) {
+      appState.agent.sendPrompt(id, text).catch((err) => {
         console.error('[agent.prompt] error:', err);
       });
     } else {
-      // No session — start a new agent
-      startAgent(id, provider, text, { cwd, model }).catch((err) => {
+      appState.agent.startAgent(id, provider, text, { cwd, model }).catch((err) => {
         console.error('[agent.start] error:', err);
       });
     }
   }
 
   function handleStop() {
-    stopAgent(id).catch((err) => {
+    appState.agent.stopAgent(id).catch((err) => {
       console.error('[agent.stop] error:', err);
     });
   }
@@ -373,7 +362,7 @@
         role="tabpanel"
         aria-label="Files"
       >
-        <FileBrowser {cwd} />
+        <FileBrowser {cwd} projectId={id} />
       </div>
 
     <!-- SSH tab -->
@@ -409,7 +398,7 @@
         role="tabpanel"
         aria-label="Comms"
       >
-        <CommsTab {groupId} agentId={id} />
+        <CommsTab {groupId} projectId={id} agentId={id} />
       </div>
 
     <!-- Tasks tab (kanban board) -->
@@ -421,7 +410,7 @@
         role="tabpanel"
         aria-label="Tasks"
       >
-        <TaskBoardTab {groupId} agentId={id} />
+        <TaskBoardTab {groupId} projectId={id} agentId={id} />
       </div>
   </div>
 </article>
diff --git a/ui-electrobun/src/mainview/TaskBoardTab.svelte b/ui-electrobun/src/mainview/TaskBoardTab.svelte
index 97248c1..b60875b 100644
--- a/ui-electrobun/src/mainview/TaskBoardTab.svelte
+++ b/ui-electrobun/src/mainview/TaskBoardTab.svelte
@@ -1,29 +1,20 @@
 <script lang="ts">
   import { appRpc } from './rpc.ts';
-
-  // ── Types ────────────────────────────────────────────────────────────
-
-  interface Task {
-    id: string;
-    title: string;
-    description: string;
-    status: string;
-    priority: string;
-    assignedTo: string | null;
-    createdBy: string;
-    groupId: string;
-    version: number;
-  }
+  import { appState, type Task } from './app-state.svelte.ts';
 
   interface Props {
     groupId: string;
+    projectId: string;
     /** Agent ID perspective for creating tasks (defaults to 'admin'). */
     agentId?: string;
   }
 
-  let { groupId, agentId = 'admin' }: Props = $props();
+  let { groupId, projectId, agentId = 'admin' }: Props = $props();
 
-  // ── State ────────────────────────────────────────────────────────────
+  // Read task state from project state tree
+  function getTasks() { return appState.project.getState(projectId).tasks; }
+
+  // ── Constants ──────────────────────────────────────────────────────
 
   const COLUMNS = ['todo', 'progress', 'review', 'done', 'blocked'] as const;
   const COL_LABELS: Record<string, string> = {
@@ -35,26 +26,11 @@
     low: 'var(--ctp-teal)',
   };
 
-  let tasks = $state<Task[]>([]);
-  let showCreateForm = $state(false);
-  let newTitle = $state('');
-  let newDesc = $state('');
-  let newPriority = $state('medium');
-  let error = $state('');
-
-  // Drag state
-  let draggedTaskId = $state<string | null>(null);
-  let dragOverCol = $state<string | null>(null);
-
-  // Fix #7 (Codex audit): Poll token to discard stale responses
-  let pollToken = $state(0);
-
   // ── Derived ──────────────────────────────────────────────────────────
 
-  // NO $derived — .reduce creates new objects every evaluation → infinite loop
   function getTasksByCol(): Record<string, Task[]> {
     return COLUMNS.reduce((acc, col) => {
-      acc[col] = tasks.filter(t => t.status === col);
+      acc[col] = getTasks().tasks.filter(t => t.status === col);
       return acc;
     }, {} as Record<string, Task[]>);
   }
@@ -62,50 +38,50 @@
   // ── Data fetching ────────────────────────────────────────────────────
 
   async function loadTasks() {
-    // Fix #7 (Codex audit): Capture token before async call, discard if stale
-    const tokenAtStart = ++pollToken;
+    const tokenAtStart = appState.project.tasks.nextPollToken(projectId);
     try {
       const res = await appRpc.request['bttask.listTasks']({ groupId });
-      if (tokenAtStart < pollToken) return; // Stale response — discard
-      tasks = res.tasks;
+      if (tokenAtStart < appState.project.tasks.getPollToken(projectId)) return;
+      appState.project.tasks.setState(projectId, 'tasks', res.tasks);
     } catch (err) {
       console.error('[TaskBoard] loadTasks:', err);
     }
   }
 
   async function createTask() {
-    const title = newTitle.trim();
-    if (!title) { error = 'Title required'; return; }
-    error = '';
+    const t = getTasks();
+    const title = t.newTitle.trim();
+    if (!title) { appState.project.tasks.setState(projectId, 'error', 'Title required'); return; }
+    appState.project.tasks.setState(projectId, 'error', '');
 
     try {
       const res = await appRpc.request['bttask.createTask']({
         title,
-        description: newDesc.trim(),
-        priority: newPriority,
+        description: t.newDesc.trim(),
+        priority: t.newPriority,
         groupId,
         createdBy: agentId,
       });
       if (res.ok) {
-        newTitle = '';
-        newDesc = '';
-        newPriority = 'medium';
-        showCreateForm = false;
+        appState.project.tasks.setMulti(projectId, {
+          newTitle: '', newDesc: '', newPriority: 'medium', showCreateForm: false,
+        });
         await loadTasks();
       } else {
-        error = res.error ?? 'Failed to create task';
+        appState.project.tasks.setState(projectId, 'error', res.error ?? 'Failed to create task');
       }
     } catch (err) {
       console.error('[TaskBoard] createTask:', err);
-      error = 'Failed to create task';
+      appState.project.tasks.setState(projectId, 'error', 'Failed to create task');
     }
   }
 
   async function moveTask(taskId: string, newStatus: string) {
-    const task = tasks.find(t => t.id === taskId);
+    const t = getTasks();
+    const task = t.tasks.find(tk => tk.id === taskId);
     if (!task || task.status === newStatus) return;
 
-    pollToken++; // Fix #7: Invalidate in-flight polls
+    appState.project.tasks.nextPollToken(projectId); // Invalidate in-flight polls
     try {
       const res = await appRpc.request['bttask.updateTaskStatus']({
         taskId,
@@ -113,13 +89,12 @@
         expectedVersion: task.version,
       });
       if (res.ok) {
-        // Optimistic update
         task.status = newStatus;
         task.version = res.newVersion ?? task.version + 1;
-        tasks = [...tasks]; // trigger reactivity
+        appState.project.tasks.setState(projectId, 'tasks', [...t.tasks]);
       } else {
-        error = res.error ?? 'Version conflict';
-        await loadTasks(); // reload on conflict
+        appState.project.tasks.setState(projectId, 'error', res.error ?? 'Version conflict');
+        await loadTasks();
       }
     } catch (err) {
       console.error('[TaskBoard] moveTask:', err);
@@ -130,7 +105,8 @@
   async function deleteTask(taskId: string) {
     try {
       await appRpc.request['bttask.deleteTask']({ taskId });
-      tasks = tasks.filter(t => t.id !== taskId);
+      appState.project.tasks.setState(projectId, 'tasks',
+        getTasks().tasks.filter(t => t.id !== taskId));
     } catch (err) {
       console.error('[TaskBoard] deleteTask:', err);
     }
@@ -139,7 +115,7 @@
   // ── Drag handlers ────────────────────────────────────────────────────
 
   function onDragStart(e: DragEvent, taskId: string) {
-    draggedTaskId = taskId;
+    appState.project.tasks.setState(projectId, 'draggedTaskId', taskId);
     if (e.dataTransfer) {
       e.dataTransfer.effectAllowed = 'move';
       e.dataTransfer.setData('text/plain', taskId);
@@ -148,38 +124,35 @@
 
   function onDragOver(e: DragEvent, col: string) {
     e.preventDefault();
-    dragOverCol = col;
+    appState.project.tasks.setState(projectId, 'dragOverCol', col);
   }
 
   function onDragLeave() {
-    dragOverCol = null;
+    appState.project.tasks.setState(projectId, 'dragOverCol', null);
   }
 
   function onDrop(e: DragEvent, col: string) {
     e.preventDefault();
-    dragOverCol = null;
-    if (draggedTaskId) {
-      moveTask(draggedTaskId, col);
-      draggedTaskId = null;
+    appState.project.tasks.setState(projectId, 'dragOverCol', null);
+    const t = getTasks();
+    if (t.draggedTaskId) {
+      moveTask(t.draggedTaskId, col);
+      appState.project.tasks.setState(projectId, 'draggedTaskId', null);
     }
   }
 
   function onDragEnd() {
-    draggedTaskId = null;
-    dragOverCol = null;
+    appState.project.tasks.setMulti(projectId, { draggedTaskId: null, dragOverCol: null });
   }
 
   // ── Init + event-driven updates (Feature 4) ─────────────────────────
 
   let pollTimer: ReturnType<typeof setInterval> | null = null;
 
-  // Feature 4: Listen for push events, fallback to 30s poll
   function onTaskChanged(payload: { groupId: string }) {
     if (!payload.groupId || payload.groupId === groupId) loadTasks();
   }
 
-  // Use onMount instead of $effect — loadTasks() writes to $state (pollToken++)
-  // which would trigger $effect re-run → infinite loop
   import { onMount } from 'svelte';
   onMount(() => {
     loadTasks();
@@ -196,38 +169,44 @@
   <!-- Toolbar -->
   <div class="tb-toolbar">
     <span class="tb-title">Task Board</span>
-    <span class="tb-count">{tasks.length} tasks</span>
-    <button class="tb-add-btn" onclick={() => { showCreateForm = !showCreateForm; }}>
-      {showCreateForm ? 'Cancel' : '+ Task'}
+    <span class="tb-count">{getTasks().tasks.length} tasks</span>
+    <button class="tb-add-btn" onclick={() => { appState.project.tasks.setState(projectId, 'showCreateForm', !getTasks().showCreateForm); }}>
+      {getTasks().showCreateForm ? 'Cancel' : '+ Task'}
     </button>
   </div>
 
   <!-- Create form -->
-  {#if showCreateForm}
+  {#if getTasks().showCreateForm}
     <div class="tb-create-form">
       <input
         class="tb-input"
         type="text"
         placeholder="Task title"
-        bind:value={newTitle}
+        value={getTasks().newTitle}
+        oninput={(e) => appState.project.tasks.setState(projectId, 'newTitle', (e.target as HTMLInputElement).value)}
         onkeydown={(e) => { if (e.key === 'Enter') createTask(); }}
       />
       <input
         class="tb-input tb-desc"
         type="text"
         placeholder="Description (optional)"
-        bind:value={newDesc}
+        value={getTasks().newDesc}
+        oninput={(e) => appState.project.tasks.setState(projectId, 'newDesc', (e.target as HTMLInputElement).value)}
       />
       <div class="tb-form-row">
-        <select class="tb-select" bind:value={newPriority}>
+        <select
+          class="tb-select"
+          value={getTasks().newPriority}
+          onchange={(e) => appState.project.tasks.setState(projectId, 'newPriority', (e.target as HTMLSelectElement).value)}
+        >
           <option value="low">Low</option>
           <option value="medium">Medium</option>
           <option value="high">High</option>
         </select>
         <button class="tb-submit" onclick={createTask}>Create</button>
       </div>
-      {#if error}
-        <span class="tb-error">{error}</span>
+      {#if getTasks().error}
+        <span class="tb-error">{getTasks().error}</span>
       {/if}
     </div>
   {/if}
@@ -237,7 +216,7 @@
     {#each COLUMNS as col}
       <div
         class="tb-column"
-        class:drag-over={dragOverCol === col}
+        class:drag-over={getTasks().dragOverCol === col}
         ondragover={(e) => onDragOver(e, col)}
         ondragleave={onDragLeave}
         ondrop={(e) => onDrop(e, col)}
@@ -253,7 +232,7 @@
           {#each getTasksByCol()[col] ?? [] as task (task.id)}
             <div
               class="tb-card"
-              class:dragging={draggedTaskId === task.id}
+              class:dragging={getTasks().draggedTaskId === task.id}
               draggable="true"
               ondragstart={(e) => onDragStart(e, task.id)}
               ondragend={onDragEnd}
diff --git a/ui-electrobun/src/mainview/TerminalTabs.svelte b/ui-electrobun/src/mainview/TerminalTabs.svelte
index 0c0a402..7eec51f 100644
--- a/ui-electrobun/src/mainview/TerminalTabs.svelte
+++ b/ui-electrobun/src/mainview/TerminalTabs.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import Terminal from './Terminal.svelte';
+  import { appState } from './app-state.svelte.ts';
 
   interface Props {
     projectId: string;
@@ -10,23 +11,10 @@
 
   let { projectId, accent = 'var(--ctp-mauve)', cwd }: Props = $props();
 
-  interface TermTab {
-    id: string;
-    title: string;
-  }
-
-  // svelte-ignore state_referenced_locally
-  const initialId = projectId;
-  const firstTabId = `${initialId}-t1`;
-
-  let tabs = $state<TermTab[]>([{ id: firstTabId, title: 'shell 1' }]);
-  let activeTabId = $state<string>(firstTabId);
-  let expanded = $state(true);
-  let counter = $state(2);
-  let mounted = $state<Set<string>>(new Set([firstTabId]));
+  // Read terminal state from project state tree
+  function getTerminals() { return appState.project.getState(projectId).terminals; }
 
   function blurTerminal() {
-    // Force-blur xterm canvas so UI buttons become clickable
     if (document.activeElement instanceof HTMLElement) {
       document.activeElement.blur();
     }
@@ -34,37 +22,23 @@
 
   function addTab() {
     blurTerminal();
-    const id = `${projectId}-t${counter}`;
-    tabs = [...tabs, { id, title: `shell ${counter}` }];
-    counter++;
-    activeTabId = id;
-    mounted = new Set([...mounted, id]);
+    appState.project.terminals.addTab(projectId);
   }
 
   function closeTab(id: string, e: MouseEvent) {
     e.stopPropagation();
     blurTerminal();
-    const idx = tabs.findIndex(t => t.id === id);
-    tabs = tabs.filter(t => t.id !== id);
-    if (activeTabId === id) {
-      const next = tabs[Math.min(idx, tabs.length - 1)];
-      activeTabId = next?.id ?? '';
-    }
-    const m = new Set(mounted);
-    m.delete(id);
-    mounted = m;
+    appState.project.terminals.closeTab(projectId, id);
   }
 
   function activateTab(id: string) {
     blurTerminal();
-    activeTabId = id;
-    if (!mounted.has(id)) mounted = new Set([...mounted, id]);
-    if (!expanded) expanded = true;
+    appState.project.terminals.activateTab(projectId, id);
   }
 
   function toggleExpand() {
     blurTerminal();
-    expanded = !expanded;
+    appState.project.terminals.toggleExpanded(projectId);
   }
 </script>
 
@@ -75,11 +49,11 @@
     <button
       class="expand-btn"
       onclick={toggleExpand}
-      title={expanded ? 'Collapse terminal' : 'Expand terminal'}
+      title={getTerminals().expanded ? 'Collapse terminal' : 'Expand terminal'}
     >
       <svg
         class="chevron"
-        class:open={expanded}
+        class:open={getTerminals().expanded}
         viewBox="0 0 24 24"
         fill="none"
         stroke="currentColor"
@@ -92,19 +66,19 @@
     </button>
 
     <div class="term-tabs" role="tablist">
-      {#each tabs as tab (tab.id)}
+      {#each getTerminals().tabs as tab (tab.id)}
         <!-- div+role="tab" allows a nested <button> for the close action -->
         <div
           class="term-tab"
-          class:active={activeTabId === tab.id}
+          class:active={getTerminals().activeTabId === tab.id}
           role="tab"
-          tabindex={activeTabId === tab.id ? 0 : -1}
-          aria-selected={activeTabId === tab.id}
+          tabindex={getTerminals().activeTabId === tab.id ? 0 : -1}
+          aria-selected={getTerminals().activeTabId === tab.id}
           onclick={() => activateTab(tab.id)}
           onkeydown={(e) => { if (e.key === 'Enter' || e.key === ' ') activateTab(tab.id); }}
         >
           <span class="tab-label">{tab.title}</span>
-          {#if tabs.length > 1}
+          {#if getTerminals().tabs.length > 1}
             <button
               class="tab-close"
               aria-label="Close {tab.title}"
@@ -119,10 +93,10 @@
 
   <!-- Terminal panes: always in DOM, display toggled.
        WebKitGTK corrupts hit-test tree on DOM add/remove during click. -->
-  <div class="term-panes" style:display={expanded ? 'block' : 'none'}>
-    {#each tabs as tab (tab.id)}
-      {#if mounted.has(tab.id)}
-        <div class="term-pane" style:display={activeTabId === tab.id ? 'flex' : 'none'}>
+  <div class="term-panes" style:display={getTerminals().expanded ? 'block' : 'none'}>
+    {#each getTerminals().tabs as tab (tab.id)}
+      {#if getTerminals().mounted.has(tab.id)}
+        <div class="term-pane" style:display={getTerminals().activeTabId === tab.id ? 'flex' : 'none'}>
           <Terminal sessionId={tab.id} {cwd} />
         </div>
       {/if}
diff --git a/ui-electrobun/src/mainview/app-state.svelte.ts b/ui-electrobun/src/mainview/app-state.svelte.ts
new file mode 100644
index 0000000..595b3a4
--- /dev/null
+++ b/ui-electrobun/src/mainview/app-state.svelte.ts
@@ -0,0 +1,190 @@
+/**
+ * Root state tree — unified API surface for all application state.
+ *
+ * Components import `appState` and access sub-domains:
+ *   appState.ui.getSettingsOpen()
+ *   appState.project.getState(id)
+ *   appState.project.terminals.addTab(id)
+ *
+ * This file is a pure re-export facade. No new state lives here.
+ */
+
+// ── UI store ──────────────────────────────────────────────────────────────
+
+import {
+  getSettingsOpen, setSettingsOpen, toggleSettings,
+  getSettingsCategory, setSettingsCategory, openSettingsCategory,
+  getPaletteOpen, setPaletteOpen, togglePalette,
+  getSearchOpen, setSearchOpen, toggleSearch,
+  getNotifDrawerOpen, setNotifDrawerOpen, toggleNotifDrawer,
+  getShowWizard, setShowWizard, toggleWizard,
+  getProjectToDelete, setProjectToDelete,
+  getShowAddGroup, setShowAddGroup, toggleAddGroup,
+  getNewGroupName, setNewGroupName, resetAddGroupForm,
+} from './ui-store.svelte.ts';
+
+// ── Workspace store ───────────────────────────────────────────────────────
+
+import {
+  getProjects, setProjects, getGroups, setGroups,
+  getActiveGroupId, setActiveGroup,
+  getFilteredProjects, getTotalCostDerived, getTotalTokensDerived,
+  getMountedGroupIds, getActiveGroup as getActiveGroupObj,
+  addProject, addProjectFromWizard, deleteProject,
+  cloneCountForProject, handleClone,
+  addGroup, loadGroupsFromDb, loadProjectsFromDb, trackAllProjects,
+  getTotalCost, getTotalTokens,
+} from './workspace-store.svelte.ts';
+
+// ── Agent store ───────────────────────────────────────────────────────────
+
+import {
+  startAgent, stopAgent, sendPrompt,
+  getSession, hasSession, clearSession,
+  loadLastSession, purgeSession, purgeProjectSessions,
+  setAgentToastFn, setRetentionConfig, loadRetentionConfig,
+  type AgentSession, type AgentMessage, type AgentStatus,
+} from './agent-store.svelte.ts';
+
+// ── Project state (per-project tree) ──────────────────────────────────────
+
+import {
+  getProjectState,
+  getActiveTab, isTabActivated, setActiveTab,
+  addTerminalTab, closeTerminalTab, activateTerminalTab, toggleTerminalExpanded,
+  setFileState, setFileMulti, nextFileRequestToken, getFileRequestToken,
+  setCommsState, setCommsMulti,
+  setTaskState, setTaskMulti, nextTaskPollToken, getTaskPollToken,
+  removeProject as removeProjectState,
+} from './project-state.svelte.ts';
+
+// ── Health store ──────────────────────────────────────────────────────────
+
+import {
+  trackProject, recordActivity, recordToolDone,
+  recordTokenSnapshot, setProjectStatus,
+  getProjectHealth, getAttentionQueue, getHealthAggregates,
+  getActiveTools, getToolHistogram,
+  untrackProject, stopHealthTick,
+} from './health-store.svelte.ts';
+
+// ── Notifications store ───────────────────────────────────────────────────
+
+import {
+  getNotifications, getNotifCount,
+  addNotification, removeNotification, clearAll as clearNotifications,
+} from './notifications-store.svelte.ts';
+
+// ── Blink store ───────────────────────────────────────────────────────────
+
+import {
+  getBlinkVisible, startBlink, stopBlink,
+} from './blink-store.svelte.ts';
+
+// ── Theme store ───────────────────────────────────────────────────────────
+
+import { themeStore } from './theme-store.svelte.ts';
+
+// ── i18n ──────────────────────────────────────────────────────────────────
+
+import { t, setLocale, getLocale, getDir } from './i18n.svelte.ts';
+
+// ── Unified API ───────────────────────────────────────────────────────────
+
+export const appState = {
+  ui: {
+    getSettingsOpen, setSettingsOpen, toggleSettings,
+    getSettingsCategory, setSettingsCategory, openSettingsCategory,
+    getPaletteOpen, setPaletteOpen, togglePalette,
+    getSearchOpen, setSearchOpen, toggleSearch,
+    getNotifDrawerOpen, setNotifDrawerOpen, toggleNotifDrawer,
+    getShowWizard, setShowWizard, toggleWizard,
+    getProjectToDelete, setProjectToDelete,
+    getShowAddGroup, setShowAddGroup, toggleAddGroup,
+    getNewGroupName, setNewGroupName, resetAddGroupForm,
+  },
+
+  workspace: {
+    getProjects, setProjects, getGroups, setGroups,
+    getActiveGroupId, setActiveGroup,
+    getFilteredProjects, getTotalCostDerived, getTotalTokensDerived,
+    getMountedGroupIds, getActiveGroup: getActiveGroupObj,
+    addProject, addProjectFromWizard, deleteProject,
+    cloneCountForProject, handleClone,
+    addGroup, loadGroupsFromDb, loadProjectsFromDb, trackAllProjects,
+    getTotalCost, getTotalTokens,
+  },
+
+  agent: {
+    startAgent, stopAgent, sendPrompt,
+    getSession, hasSession, clearSession,
+    loadLastSession, purgeSession, purgeProjectSessions,
+    setToastFn: setAgentToastFn,
+    setRetentionConfig, loadRetentionConfig,
+  },
+
+  project: {
+    getState: getProjectState,
+    removeState: removeProjectState,
+
+    tab: {
+      getActiveTab, isTabActivated, setActiveTab,
+    },
+
+    terminals: {
+      addTab: addTerminalTab,
+      closeTab: closeTerminalTab,
+      activateTab: activateTerminalTab,
+      toggleExpanded: toggleTerminalExpanded,
+    },
+
+    files: {
+      setState: setFileState,
+      setMulti: setFileMulti,
+      nextRequestToken: nextFileRequestToken,
+      getRequestToken: getFileRequestToken,
+    },
+
+    comms: {
+      setState: setCommsState,
+      setMulti: setCommsMulti,
+    },
+
+    tasks: {
+      setState: setTaskState,
+      setMulti: setTaskMulti,
+      nextPollToken: nextTaskPollToken,
+      getPollToken: getTaskPollToken,
+    },
+  },
+
+  health: {
+    trackProject, recordActivity, recordToolDone,
+    recordTokenSnapshot, setProjectStatus,
+    getProjectHealth, getAttentionQueue, getHealthAggregates,
+    getActiveTools, getToolHistogram,
+    untrackProject, stopHealthTick,
+  },
+
+  notifications: {
+    getAll: getNotifications, getCount: getNotifCount,
+    add: addNotification, remove: removeNotification, clear: clearNotifications,
+  },
+
+  blink: {
+    getVisible: getBlinkVisible, start: startBlink, stop: stopBlink,
+  },
+
+  theme: themeStore,
+
+  i18n: { t, setLocale, getLocale, getDir },
+} as const;
+
+// Re-export types for convenience
+export type { AgentSession, AgentMessage, AgentStatus };
+export type {
+  ProjectState, TermTab, TerminalState, FileState,
+  CommsState, TaskState, TabState, DirEntry,
+  Channel, ChannelMessage, CommsAgent, DM, ChannelMember, Task,
+  ProjectTab,
+} from './project-state.types.ts';
diff --git a/ui-electrobun/src/mainview/project-state.svelte.ts b/ui-electrobun/src/mainview/project-state.svelte.ts
new file mode 100644
index 0000000..755c664
--- /dev/null
+++ b/ui-electrobun/src/mainview/project-state.svelte.ts
@@ -0,0 +1,247 @@
+/**
+ * Per-project state tree — unified state for all project sub-domains.
+ *
+ * Uses version counter pattern (not Map reassignment) to avoid
+ * Svelte 5 infinite reactive loops. Plain Map is NOT reactive;
+ * _version is the sole reactive signal.
+ *
+ * Components read via getter functions (which read _version to subscribe)
+ * and mutate via action functions (which bump _version to notify).
+ */
+
+import type {
+  ProjectTab, ProjectState, FileState, CommsState, TaskState,
+} from './project-state.types.ts';
+
+export type {
+  ProjectTab, ProjectState, TerminalState, FileState,
+  CommsState, TaskState, TabState, DirEntry,
+  TermTab, Channel, ChannelMessage, CommsAgent, DM, ChannelMember, Task,
+} from './project-state.types.ts';
+
+// ── Internal state ────────────────────────────────────────────────────────
+
+const _projects = new Map<string, ProjectState>();
+let _version = $state(0);
+
+// ── Factory ───────────────────────────────────────────────────────────────
+
+function createProjectState(projectId: string): ProjectState {
+  const firstTabId = `${projectId}-t1`;
+  return {
+    terminals: {
+      tabs: [{ id: firstTabId, title: 'shell 1' }],
+      activeTabId: firstTabId,
+      expanded: true,
+      nextId: 2,
+      mounted: new Set([firstTabId]),
+    },
+    files: {
+      childrenCache: new Map(),
+      openDirs: new Set(),
+      loadingDirs: new Set(),
+      selectedFile: null,
+      fileContent: null,
+      fileEncoding: 'utf8',
+      fileSize: 0,
+      fileError: null,
+      fileLoading: false,
+      isDirty: false,
+      editorContent: '',
+      fileRequestToken: 0,
+      readMtimeMs: 0,
+      showConflictDialog: false,
+    },
+    comms: {
+      mode: 'channels',
+      channels: [],
+      agents: [],
+      activeChannelId: null,
+      activeDmAgentId: null,
+      channelMessages: [],
+      dmMessages: [],
+      input: '',
+      loading: false,
+      channelMembers: [],
+      showMembers: false,
+    },
+    tasks: {
+      tasks: [],
+      showCreateForm: false,
+      newTitle: '',
+      newDesc: '',
+      newPriority: 'medium',
+      error: '',
+      draggedTaskId: null,
+      dragOverCol: null,
+      pollToken: 0,
+    },
+    tab: {
+      activeTab: 'model',
+      activatedTabs: new Set<ProjectTab>(['model']),
+    },
+  };
+}
+
+function ensureProject(projectId: string): ProjectState {
+  let state = _projects.get(projectId);
+  if (!state) {
+    state = createProjectState(projectId);
+    _projects.set(projectId, state);
+  }
+  return state;
+}
+
+// ── Generic getter (reads _version for reactivity) ────────────────────────
+
+export function getProjectState(projectId: string): ProjectState {
+  void _version;
+  return ensureProject(projectId);
+}
+
+// ── Version bump (called by all actions) ──────────────────────────────────
+
+function bump(): void { _version++; }
+
+// ── Tab actions ───────────────────────────────────────────────────────────
+
+export function getActiveTab(projectId: string): ProjectTab {
+  void _version;
+  return _projects.get(projectId)?.tab.activeTab ?? 'model';
+}
+
+export function isTabActivated(projectId: string, tab: ProjectTab): boolean {
+  void _version;
+  return _projects.get(projectId)?.tab.activatedTabs.has(tab) ?? (tab === 'model');
+}
+
+export function setActiveTab(projectId: string, tab: ProjectTab): void {
+  const state = ensureProject(projectId);
+  state.tab.activeTab = tab;
+  state.tab.activatedTabs.add(tab);
+  bump();
+}
+
+// ── Terminal actions ──────────────────────────────────────────────────────
+
+export function addTerminalTab(projectId: string): void {
+  const t = ensureProject(projectId).terminals;
+  const id = `${projectId}-t${t.nextId}`;
+  t.tabs = [...t.tabs, { id, title: `shell ${t.nextId}` }];
+  t.nextId++;
+  t.activeTabId = id;
+  t.mounted.add(id);
+  bump();
+}
+
+export function closeTerminalTab(projectId: string, tabId: string): void {
+  const t = ensureProject(projectId).terminals;
+  const idx = t.tabs.findIndex(tab => tab.id === tabId);
+  t.tabs = t.tabs.filter(tab => tab.id !== tabId);
+  if (t.activeTabId === tabId) {
+    const next = t.tabs[Math.min(idx, t.tabs.length - 1)];
+    t.activeTabId = next?.id ?? '';
+  }
+  t.mounted.delete(tabId);
+  bump();
+}
+
+export function activateTerminalTab(projectId: string, tabId: string): void {
+  const t = ensureProject(projectId).terminals;
+  t.activeTabId = tabId;
+  t.mounted.add(tabId);
+  if (!t.expanded) t.expanded = true;
+  bump();
+}
+
+export function toggleTerminalExpanded(projectId: string): void {
+  const t = ensureProject(projectId).terminals;
+  t.expanded = !t.expanded;
+  bump();
+}
+
+// ── File actions ──────────────────────────────────────────────────────────
+
+export function setFileState<K extends keyof FileState>(
+  projectId: string, key: K, value: FileState[K],
+): void {
+  const f = ensureProject(projectId).files;
+  f[key] = value;
+  bump();
+}
+
+export function setFileMulti(
+  projectId: string, updates: Partial<FileState>,
+): void {
+  const f = ensureProject(projectId).files;
+  for (const [k, v] of Object.entries(updates)) {
+    (f as unknown as Record<string, unknown>)[k] = v;
+  }
+  bump();
+}
+
+export function nextFileRequestToken(projectId: string): number {
+  const f = ensureProject(projectId).files;
+  return ++f.fileRequestToken;
+}
+
+export function getFileRequestToken(projectId: string): number {
+  void _version;
+  return ensureProject(projectId).files.fileRequestToken;
+}
+
+// ── Comms actions ─────────────────────────────────────────────────────────
+
+export function setCommsState<K extends keyof CommsState>(
+  projectId: string, key: K, value: CommsState[K],
+): void {
+  const c = ensureProject(projectId).comms;
+  c[key] = value;
+  bump();
+}
+
+export function setCommsMulti(
+  projectId: string, updates: Partial<CommsState>,
+): void {
+  const c = ensureProject(projectId).comms;
+  for (const [k, v] of Object.entries(updates)) {
+    (c as unknown as Record<string, unknown>)[k] = v;
+  }
+  bump();
+}
+
+// ── Task actions ──────────────────────────────────────────────────────────
+
+export function setTaskState<K extends keyof TaskState>(
+  projectId: string, key: K, value: TaskState[K],
+): void {
+  const t = ensureProject(projectId).tasks;
+  t[key] = value;
+  bump();
+}
+
+export function setTaskMulti(
+  projectId: string, updates: Partial<TaskState>,
+): void {
+  const t = ensureProject(projectId).tasks;
+  for (const [k, v] of Object.entries(updates)) {
+    (t as unknown as Record<string, unknown>)[k] = v;
+  }
+  bump();
+}
+
+export function nextTaskPollToken(projectId: string): number {
+  const t = ensureProject(projectId).tasks;
+  return ++t.pollToken;
+}
+
+export function getTaskPollToken(projectId: string): number {
+  void _version;
+  return ensureProject(projectId).tasks.pollToken;
+}
+
+// ── Cleanup ───────────────────────────────────────────────────────────────
+
+export function removeProject(projectId: string): void {
+  if (_projects.delete(projectId)) bump();
+}
diff --git a/ui-electrobun/src/mainview/project-state.types.ts b/ui-electrobun/src/mainview/project-state.types.ts
new file mode 100644
index 0000000..d45fa74
--- /dev/null
+++ b/ui-electrobun/src/mainview/project-state.types.ts
@@ -0,0 +1,154 @@
+/**
+ * Per-project state tree — type definitions.
+ *
+ * Separated from project-state.svelte.ts to keep that file under 300 lines.
+ * This file is plain .ts (no runes needed).
+ */
+
+import type { ProjectTab } from './project-tabs-store.svelte.ts';
+export type { ProjectTab };
+
+// ── Terminal ──────────────────────────────────────────────────────────────
+
+export interface TermTab {
+  id: string;
+  title: string;
+}
+
+export interface TerminalState {
+  tabs: TermTab[];
+  activeTabId: string;
+  expanded: boolean;
+  nextId: number;
+  mounted: Set<string>;
+}
+
+// ── Files ─────────────────────────────────────────────────────────────────
+
+export interface DirEntry {
+  name: string;
+  type: 'file' | 'dir';
+  size: number;
+}
+
+export interface FileState {
+  childrenCache: Map<string, DirEntry[]>;
+  openDirs: Set<string>;
+  loadingDirs: Set<string>;
+  selectedFile: string | null;
+  fileContent: string | null;
+  fileEncoding: 'utf8' | 'base64';
+  fileSize: number;
+  fileError: string | null;
+  fileLoading: boolean;
+  isDirty: boolean;
+  editorContent: string;
+  fileRequestToken: number;
+  readMtimeMs: number;
+  showConflictDialog: boolean;
+}
+
+// ── Comms ─────────────────────────────────────────────────────────────────
+
+export interface Channel {
+  id: string;
+  name: string;
+  groupId: string;
+  createdBy: string;
+  memberCount: number;
+  createdAt: string;
+}
+
+export interface ChannelMessage {
+  id: string;
+  channelId: string;
+  fromAgent: string;
+  content: string;
+  createdAt: string;
+  senderName: string;
+  senderRole: string;
+}
+
+export interface CommsAgent {
+  id: string;
+  name: string;
+  role: string;
+  groupId: string;
+  tier: number;
+  status: string;
+  unreadCount: number;
+}
+
+export interface DM {
+  id: string;
+  fromAgent: string;
+  toAgent: string;
+  content: string;
+  read: boolean;
+  createdAt: string;
+  senderName: string | null;
+  senderRole: string | null;
+}
+
+export interface ChannelMember {
+  agentId: string;
+  name: string;
+  role: string;
+}
+
+export interface CommsState {
+  mode: 'channels' | 'dms';
+  channels: Channel[];
+  agents: CommsAgent[];
+  activeChannelId: string | null;
+  activeDmAgentId: string | null;
+  channelMessages: ChannelMessage[];
+  dmMessages: DM[];
+  input: string;
+  loading: boolean;
+  channelMembers: ChannelMember[];
+  showMembers: boolean;
+}
+
+// ── Tasks ─────────────────────────────────────────────────────────────────
+
+export interface Task {
+  id: string;
+  title: string;
+  description: string;
+  status: string;
+  priority: string;
+  assignedTo: string | null;
+  createdBy: string;
+  groupId: string;
+  version: number;
+}
+
+export interface TaskState {
+  tasks: Task[];
+  showCreateForm: boolean;
+  newTitle: string;
+  newDesc: string;
+  newPriority: string;
+  error: string;
+  draggedTaskId: string | null;
+  dragOverCol: string | null;
+  pollToken: number;
+}
+
+// ── Tabs ──────────────────────────────────────────────────────────────────
+
+export interface TabState {
+  activeTab: ProjectTab;
+  activatedTabs: Set<ProjectTab>;
+}
+
+// ── Root per-project state ────────────────────────────────────────────────
+
+export interface ProjectState {
+  terminals: TerminalState;
+  files: FileState;
+  comms: CommsState;
+  tasks: TaskState;
+  tab: TabState;
+}