feat(v2): add SSH management, ctx integration, themes, detached mode, auto-updater

SSH session management:
- SshSession struct + ssh_sessions SQLite table in session.rs
- CRUD Tauri commands (ssh_session_list/save/delete) in lib.rs
- SshDialog.svelte (create/edit modal), SshSessionList.svelte (sidebar)
- SSH pane routes to TerminalPane with shell=/usr/bin/ssh + args

ctx context database integration:
- ctx.rs: read-only CtxDb (SQLITE_OPEN_READ_ONLY for ~/.claude-context/context.db)
- 5 Tauri commands (ctx_list_projects/get_context/get_shared/get_summaries/search)
- ContextPane.svelte with project selector, tabs, search
- ctx-bridge.ts adapter

Catppuccin theme flavors (Latte/Frappe/Macchiato/Mocha):
- themes.ts: all 4 palette definitions + buildXtermTheme/applyCssVariables
- theme.svelte.ts: reactive store with SQLite persistence
- SettingsDialog flavor dropdown, TerminalPane theme-aware

Detached pane mode (pop-out windows):
- detach.ts: isDetachedMode/getDetachedConfig from URL params
- App.svelte: conditional rendering of single pane without chrome

Other additions:
- Shiki syntax highlighting (highlight.ts, lazy singleton, 13 languages)
- Tauri auto-updater plugin (tauri-plugin-updater + updater.ts)
- AgentPane markdown rendering with Shiki code highlighting
- New deps: shiki, @tauri-apps/plugin-updater, tauri-plugin-updater

v2/src/lib/agent-dispatcher.ts

@@ -1,7 +1,7 @@
 // Agent Dispatcher — connects sidecar bridge events to agent store
 // Single listener that routes sidecar messages to the correct agent session
 
-import { onSidecarMessage, onSidecarExited, type SidecarMessage } from './adapters/agent-bridge';
+import { onSidecarMessage, onSidecarExited, restartAgent, type SidecarMessage } from './adapters/agent-bridge';
 import { adaptSDKMessage } from './adapters/sdk-messages';
 import type { InitContent, CostContent } from './adapters/sdk-messages';
 import {
@@ -19,6 +19,10 @@ let unlistenExit: (() => void) | null = null;
 
 // Sidecar liveness — checked by UI components
 let sidecarAlive = true;
+
+// Sidecar crash recovery state
+const MAX_RESTART_ATTEMPTS = 3;
+let restartAttempts = 0;
 export function isSidecarAlive(): boolean {
   return sidecarAlive;
 }
@@ -33,6 +37,11 @@ export async function startAgentDispatcher(): Promise<void> {
 
   unlistenMsg = await onSidecarMessage((msg: SidecarMessage) => {
     sidecarAlive = true;
+    // Reset restart counter on any successful message — sidecar recovered
+    if (restartAttempts > 0) {
+      notify('success', 'Sidecar recovered');
+      restartAttempts = 0;
+    }
 
     const sessionId = msg.sessionId;
     if (!sessionId) return;
@@ -61,15 +70,33 @@ export async function startAgentDispatcher(): Promise<void> {
     }
   });
 
-  unlistenExit = await onSidecarExited(() => {
+  unlistenExit = await onSidecarExited(async () => {
     sidecarAlive = false;
-    notify('error', 'Sidecar process crashed — agent features unavailable');
     // Mark all running sessions as errored
     for (const session of getAgentSessions()) {
       if (session.status === 'running' || session.status === 'starting') {
         updateAgentStatus(session.id, 'error', 'Sidecar crashed');
       }
     }
+
+    // Attempt auto-restart with exponential backoff
+    if (restartAttempts < MAX_RESTART_ATTEMPTS) {
+      restartAttempts++;
+      const delayMs = 1000 * Math.pow(2, restartAttempts - 1); // 1s, 2s, 4s
+      notify('warning', `Sidecar crashed, restarting (attempt ${restartAttempts}/${MAX_RESTART_ATTEMPTS})...`);
+      await new Promise((resolve) => setTimeout(resolve, delayMs));
+      try {
+        await restartAgent();
+        sidecarAlive = true;
+        // Note: restartAttempts is reset when next sidecar message arrives
+      } catch {
+        if (restartAttempts >= MAX_RESTART_ATTEMPTS) {
+          notify('error', `Sidecar restart failed after ${MAX_RESTART_ATTEMPTS} attempts`);
+        }
+      }
+    } else {
+      notify('error', `Sidecar restart failed after ${MAX_RESTART_ATTEMPTS} attempts`);
+    }
   });
 }