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/stores/theme.svelte.ts

@@ -0,0 +1,47 @@
+// Theme store — persists Catppuccin flavor selection via settings bridge
+
+import { getSetting, setSetting } from '../adapters/settings-bridge';
+import {
+  type CatppuccinFlavor,
+  buildXtermTheme,
+  applyCssVariables,
+  type XtermTheme,
+} from '../styles/themes';
+
+let currentFlavor = $state<CatppuccinFlavor>('mocha');
+
+export function getCurrentFlavor(): CatppuccinFlavor {
+  return currentFlavor;
+}
+
+export function getXtermTheme(): XtermTheme {
+  return buildXtermTheme(currentFlavor);
+}
+
+/** Change flavor, apply CSS variables, and persist to settings DB */
+export async function setFlavor(flavor: CatppuccinFlavor): Promise<void> {
+  currentFlavor = flavor;
+  applyCssVariables(flavor);
+  try {
+    await setSetting('theme', flavor);
+  } catch (e) {
+    console.error('Failed to persist theme setting:', e);
+  }
+}
+
+/** Load saved flavor from settings DB and apply. Call once on app startup. */
+export async function initTheme(): Promise<void> {
+  try {
+    const saved = await getSetting('theme');
+    if (saved && ['latte', 'frappe', 'macchiato', 'mocha'].includes(saved)) {
+      currentFlavor = saved as CatppuccinFlavor;
+    }
+  } catch {
+    // Fall back to default (mocha) — catppuccin.css provides Mocha defaults
+  }
+  // Always apply to sync CSS vars with current flavor
+  // (skip if mocha — catppuccin.css already has Mocha values)
+  if (currentFlavor !== 'mocha') {
+    applyCssVariables(currentFlavor);
+  }
+}