fix(electrobun): eliminate remaining reactive cycles (tabs store + palette)

project-tabs-store: replaced Map reassignment (_tabs = new Map(_tabs)) with
version counter pattern. Map reassignment created new object reference on
every getActiveTab() call from $derived → infinite loop.

CommandPalette: replaced $derived COMMANDS array with plain function call.
$derived with .map() created new array every evaluation → infinite loop
when any i18n state changed.

ui-electrobun/src/mainview/CommandPalette.svelte

@@ -55,15 +55,17 @@
     { id: 'zoom-out',        labelKey: 'palette.zoomOut',         shortcut: 'Ctrl+-',         action: () => dispatch('zoom-out') },
   ];
 
-  let COMMANDS = $derived<Command[]>(
-    COMMAND_DEFS.map(d => ({
+  // Build commands once — NOT $derived (creating new array per evaluation causes loops)
+  function buildCommands(): Command[] {
+    return COMMAND_DEFS.map(d => ({
       id: d.id,
       label: t(d.labelKey as any),
       description: d.descKey ? t(d.descKey as any) : undefined,
       shortcut: d.shortcut,
       action: d.action,
-    }))
-  );
+    }));
+  }
+  let COMMANDS = buildCommands();
 
   let query = $state('');
   let selectedIdx = $state(0);

ui-electrobun/src/mainview/project-tabs-store.svelte.ts

@@ -1,13 +1,11 @@
 /**
  * Project tabs store — per-project tab state.
  *
- * Tracks which tab is active and which tabs have been activated (PERSISTED-LAZY
- * pattern) for each project card. This allows cross-component access — e.g.,
- * StatusBar can show which tab is active, palette commands can switch tabs.
+ * Uses a version counter to signal changes instead of Map reassignment.
+ * Map reassignment (`_tabs = new Map(_tabs)`) caused infinite reactive loops
+ * in Svelte 5 because each call created a new object reference.
  */
 
-// ── Types ────────────────────────────────────────────────────────────────
-
 export type ProjectTab =
   | 'model' | 'docs' | 'context' | 'files'
   | 'ssh' | 'memory' | 'comms' | 'tasks';
@@ -23,7 +21,9 @@ interface TabState {
 
 // ── State ────────────────────────────────────────────────────────────────
 
-let _tabs = $state<Map<string, TabState>>(new Map());
+// Plain Map — NOT reactive. We use _version to signal changes.
+const _tabs = new Map<string, TabState>();
+let _version = $state(0);
 
 // ── Internal helper ──────────────────────────────────────────────────────
 
@@ -32,36 +32,35 @@ function ensureEntry(projectId: string): TabState {
   if (!entry) {
     entry = { activeTab: 'model', activatedTabs: new Set(['model']) };
     _tabs.set(projectId, entry);
-    // Trigger reactivity by reassigning the map
-    _tabs = new Map(_tabs);
+    // Do NOT bump version here — this is a read-path side effect
+    // that would cause infinite loops when called from $derived
   }
   return entry;
 }
 
-// ── Getters ──────────────────────────────────────────────────────────────
+// ── Getters (read _version to subscribe to changes) ─────────────────────
 
 export function getActiveTab(projectId: string): ProjectTab {
+  void _version; // subscribe to version counter
   return _tabs.get(projectId)?.activeTab ?? 'model';
 }
 
 export function isTabActivated(projectId: string, tab: ProjectTab): boolean {
+  void _version;
   return _tabs.get(projectId)?.activatedTabs.has(tab) ?? (tab === 'model');
 }
 
-// ── Actions ──────────────────────────────────────────────────────────────
+// ── Actions (bump version to notify subscribers) ────────────────────────
 
 export function setActiveTab(projectId: string, tab: ProjectTab): void {
   const entry = ensureEntry(projectId);
   entry.activeTab = tab;
-  entry.activatedTabs = new Set([...entry.activatedTabs, tab]);
-  // Trigger reactivity
-  _tabs = new Map(_tabs);
+  entry.activatedTabs.add(tab);
+  _version++; // signal change without creating new objects
 }
 
-/** Remove tab state when a project is deleted. */
 export function removeProject(projectId: string): void {
-  if (_tabs.has(projectId)) {
-    _tabs.delete(projectId);
-    _tabs = new Map(_tabs);
+  if (_tabs.delete(projectId)) {
+    _version++;
   }
 }