refactor(desktop): make Tauri thin shell running web sidecar (#273)

## What / Why
This PR finishes the desktop refactor: the Tauri app is now a thin shell that launches the web server as a sidecar and loads the UI from `http://127.0.0.1:<port>`. All real backend logic lives in `packages/web/server/index.js`; desktop Rust keeps only native integrations (menu/dialog/notifications/updater/deep-link + window chrome).
This unblocks:
- consistent behavior across web/desktop/vscode (single backend)
- simpler desktop maintenance (no duplicated Rust backend)
- host switching between Local + remote instances in desktop
- reliable cold-start behavior on slow machines (VSCode + desktop)
## Key changes
- Desktop sidecar runtime
  - build pipeline to bundle web dist + `openchamber-server` sidecar (`packages/desktop/scripts/build-sidecar.mjs`)
  - robust local port selection (prefer saved/default, fallback to random; persisted in `~/.config/openchamber/settings.json`)
  - improved PATH handling so the sidecar can locate `opencode` CLI (incl `~/.opencode/bin`, overrides, common bins)
  - disable native right-click context menu in production builds (dev keeps it)
- Desktop instance switcher (Tauri-only)
  - header button + modal to add/edit/delete remote hosts, set default, probe status/ping, switch back to Local escape hatch
  - auth gate includes host switcher so you can recover when a remote host is broken/auth-required
  - host list stored desktop-locally (not tied to the currently selected remote server)
- Notifications
  - decision logic moved server-side; desktop notifications emitted via sidecar stdout and shown natively by Tauri
  - prevent double-notifications on desktop Local origin (UI ignores SSE notification when native path is active)
  - restore macOS notification sound
- Updates
  - Tauri updater used only when viewing Local instance in desktop shell (avoid “remote web update” triggering desktop restart)
- Settings persistence & UX polish
  - persist model favorites/recents via `/api/config/settings` (works for web + desktop; not origin-dependent)
  - persist per-project sidebar collapse state in `projects[].sidebarCollapsed` via `/api/config/settings` (with debounce on toggles)
  - macOS header sizing/traffic-lights offsets fixed (marketing macOS major injected from desktop; MultiRun header aligned)
  - VSCode cold-start: keep retrying provider/agent loads after connection to avoid empty UI on slow machines
  - misc lint/type fixes + bun.lock sync
- Desktop bootstrap / resiliency
  - show onboarding screen when OpenCode CLI is missing (desktop Local origin), with retry hook to restart OpenCode after install
## Testing notes
- Desktop (macOS): switch Local <-> remote, set default host, verify auth gate recovery, native notifications (with sound), updater gated to Local
- Web: favorites/recents + per-project collapsed state persist across reload/restart
- VSCode: slow startup no longer results in missing providers/agents/models

packages/ui/src/stores/types/sessionTypes.ts

@@ -134,7 +134,12 @@ export interface SessionStore {
 
     sessionAgentEditModes: Map<string, Map<string, EditPermissionMode>>;
 
-    sessionActivityPhase?: Map<string, 'idle' | 'busy' | 'cooldown'>;
+    // Server-owned session status (mirrors OpenCode SessionStatus: busy|retry|idle).
+    // Use as the single source of truth for "assistant working" UI.
+    sessionStatus?: Map<
+        string,
+        { type: 'idle' | 'busy' | 'retry'; attempt?: number; message?: string; next?: number }
+    >;
 
     userSummaryTitles: Map<string, { title: string; createdAt: number | null }>;
 

packages/ui/src/stores/useConfigStore.ts

@@ -8,7 +8,6 @@ import type { ModelMetadata } from "@/types";
 import { getSafeStorage } from "./utils/safeStorage";
 import type { SessionStore } from "./types/sessionTypes";
 import { filterVisibleAgents } from "./useAgentsStore";
-import { isDesktopRuntime, getDesktopSettings } from "@/lib/desktop";
 import { getRegisteredRuntimeAPIs } from "@/contexts/runtimeAPIRegistry";
 import { updateDesktopSettings } from "@/lib/persistence";
 import { useDirectoryStore } from "@/stores/useDirectoryStore";
@@ -30,19 +29,7 @@ interface OpenChamberDefaults {
 
 const fetchOpenChamberDefaults = async (): Promise<OpenChamberDefaults> => {
     try {
-        // 1. Desktop runtime (Tauri)
-        if (isDesktopRuntime()) {
-            const settings = await getDesktopSettings();
-            return {
-                defaultModel: settings?.defaultModel,
-                defaultVariant: settings?.defaultVariant,
-                defaultAgent: settings?.defaultAgent,
-                autoCreateWorktree: settings?.autoCreateWorktree,
-                gitmojiEnabled: settings?.gitmojiEnabled,
-            };
-        }
-
-        // 2. Runtime settings API (VSCode)
+        // 1. Runtime settings API (VSCode)
         const runtimeSettings = getRegisteredRuntimeAPIs()?.settings;
         if (runtimeSettings) {
             try {
@@ -67,7 +54,7 @@ const fetchOpenChamberDefaults = async (): Promise<OpenChamberDefaults> => {
             }
         }
 
-        // 3. Fetch API (Web)
+        // 2. Fetch API (Web/server)
         const response = await fetch('/api/config/settings', {
             method: 'GET',
             headers: { Accept: 'application/json' },

packages/ui/src/stores/useDirectoryStore.ts

@@ -85,9 +85,7 @@ const getHomeDirectory = () => {
     const desktopHome =
       (typeof window.__OPENCHAMBER_HOME__ === 'string' && window.__OPENCHAMBER_HOME__.length > 0
         ? window.__OPENCHAMBER_HOME__
-        : window.opencodeDesktop && typeof window.opencodeDesktop.homeDirectory === 'string'
-          ? window.opencodeDesktop.homeDirectory
-          : null);
+        : null);
 
     if (desktopHome && desktopHome.length > 0) {
       cachedHomeDirectory = desktopHome;

packages/ui/src/stores/useGitIdentitiesStore.ts

@@ -10,7 +10,6 @@ import {
   discoverGitCredentials,
   getGlobalGitIdentity
 } from "@/lib/gitApi";
-import { getDesktopSettings, isDesktopRuntime } from "@/lib/desktop";
 import { updateDesktopSettings } from "@/lib/persistence";
 import { getRegisteredRuntimeAPIs } from "@/contexts/runtimeAPIRegistry";
 
@@ -145,10 +144,7 @@ export const useGitIdentitiesStore = create<GitIdentitiesStore>()(
           try {
             let defaultId: string | null = null;
 
-            if (isDesktopRuntime()) {
-              const settings = await getDesktopSettings();
-              defaultId = normalize((settings as { defaultGitIdentityId?: unknown } | null | undefined)?.defaultGitIdentityId);
-            } else {
+            if (defaultId === null) {
               const runtimeSettings = getRegisteredRuntimeAPIs()?.settings;
               if (runtimeSettings) {
                 try {
@@ -159,20 +155,20 @@ export const useGitIdentitiesStore = create<GitIdentitiesStore>()(
                   // fall through
                 }
               }
+            }
 
-              if (defaultId === null) {
-                try {
-                  const response = await fetch('/api/config/settings', {
-                    method: 'GET',
-                    headers: { Accept: 'application/json' },
-                  });
-                  if (response.ok) {
-                    const data = (await response.json().catch(() => null)) as Record<string, unknown> | null;
-                    defaultId = normalize(data?.defaultGitIdentityId);
-                  }
-                } catch {
-                  // ignore
+            if (defaultId === null) {
+              try {
+                const response = await fetch('/api/config/settings', {
+                  method: 'GET',
+                  headers: { Accept: 'application/json' },
+                });
+                if (response.ok) {
+                  const data = (await response.json().catch(() => null)) as Record<string, unknown> | null;
+                  defaultId = normalize(data?.defaultGitIdentityId);
                 }
+              } catch {
+                // ignore
               }
             }
 

packages/ui/src/stores/useProjectsStore.ts

@@ -121,6 +121,9 @@ const sanitizeProjects = (value: unknown): ProjectEntry[] => {
     if (typeof candidate.lastOpenedAt === 'number' && Number.isFinite(candidate.lastOpenedAt) && candidate.lastOpenedAt >= 0) {
       project.lastOpenedAt = candidate.lastOpenedAt;
     }
+    if (typeof candidate.sidebarCollapsed === 'boolean') {
+      project.sidebarCollapsed = candidate.sidebarCollapsed;
+    }
     if (candidate.worktreeDefaults && typeof candidate.worktreeDefaults === 'object') {
       const wt = candidate.worktreeDefaults as Record<string, unknown>;
       const defaults: WorktreeDefaults = {};

packages/ui/src/stores/useQuotaStore.ts

@@ -3,7 +3,7 @@ import { create } from 'zustand';
 import { devtools } from 'zustand/middleware';
 import type { ProviderResult, QuotaProviderId } from '@/types';
 import { QUOTA_PROVIDERS } from '@/lib/quota';
-import { getDesktopSettings, isDesktopRuntime, isVSCodeRuntime } from '@/lib/desktop';
+import { isVSCodeRuntime } from '@/lib/desktop';
 import { getRegisteredRuntimeAPIs } from '@/contexts/runtimeAPIRegistry';
 
 const DEFAULT_REFRESH_INTERVAL_MS = 60000;
@@ -57,11 +57,6 @@ const parseSettings = (data: Record<string, unknown> | null): QuotaSettingsState
 };
 
 const loadSettingsFromRuntime = async (): Promise<QuotaSettingsState> => {
-  if (isDesktopRuntime()) {
-    const data = await getDesktopSettings();
-    return parseSettings((data as Record<string, unknown>) ?? null);
-  }
-
   const runtimeSettings = getRegisteredRuntimeAPIs()?.settings;
   if (runtimeSettings) {
     try {

packages/ui/src/stores/useSessionStore.ts

@@ -98,7 +98,7 @@ export const useSessionStore = create<SessionStore>()(
             sessionAgentEditModes: new Map(),
             abortPromptSessionId: null,
             abortPromptExpiresAt: null,
-            sessionActivityPhase: new Map(),
+            sessionStatus: new Map(),
             userSummaryTitles: new Map(),
             pendingInputText: null,
             newSessionDraft: { open: true, directoryOverride: null, parentID: null },
@@ -315,19 +315,11 @@ export const useSessionStore = create<SessionStore>()(
                     const draft = get().newSessionDraft;
                     const trimmedAgent = typeof agent === 'string' && agent.trim().length > 0 ? agent.trim() : undefined;
 
-                    const setBusyPhase = (sessionId: string) => {
+                    const setStatus = (sessionId: string, type: 'idle' | 'busy') => {
                         set((state) => {
-                            const next = new Map(state.sessionActivityPhase ?? new Map());
-                            next.set(sessionId, 'busy');
-                            return { sessionActivityPhase: next };
-                        });
-                    };
-
-                    const setIdlePhase = (sessionId: string) => {
-                        set((state) => {
-                            const next = new Map(state.sessionActivityPhase ?? new Map());
-                            next.set(sessionId, 'idle');
-                            return { sessionActivityPhase: next };
+                            const next = new Map(state.sessionStatus ?? new Map());
+                            next.set(sessionId, { type });
+                            return { sessionStatus: next };
                         });
                     };
 
@@ -391,14 +383,14 @@ export const useSessionStore = create<SessionStore>()(
                         }
 
                         get().closeNewSessionDraft();
-                        setBusyPhase(created.id);
+                        setStatus(created.id, 'busy');
 
                         try {
                             return await useMessageStore
                                 .getState()
                                 .sendMessage(content, providerID, modelID, effectiveDraftAgent, created.id, attachments, agentMentionName, additionalParts, variant);
                         } catch (error) {
-                            setIdlePhase(created.id);
+                            setStatus(created.id, 'idle');
                             throw error;
                         }
                     }
@@ -429,14 +421,14 @@ export const useSessionStore = create<SessionStore>()(
                     }
  
                     if (currentSessionId) {
-                        setBusyPhase(currentSessionId);
+                        setStatus(currentSessionId, 'busy');
                     }
 
                     try {
                         return await useMessageStore.getState().sendMessage(content, providerID, modelID, effectiveAgent, currentSessionId || undefined, attachments, agentMentionName, additionalParts, variant);
                     } catch (error) {
                         if (currentSessionId) {
-                            setIdlePhase(currentSessionId);
+                            setStatus(currentSessionId, 'idle');
                         }
                         throw error;
                     }
@@ -504,9 +496,9 @@ export const useSessionStore = create<SessionStore>()(
                 updateViewportAnchor: (sessionId: string, anchor: number) => useMessageStore.getState().updateViewportAnchor(sessionId, anchor),
                 trimToViewportWindow: (sessionId: string, targetSize?: number) => {
                     const currentSessionId = useSessionManagementStore.getState().currentSessionId;
-                    // Skip trimming for sessions in active phase (busy/cooldown)
-                    const phase = get().sessionActivityPhase?.get(sessionId);
-                    if (phase === 'busy' || phase === 'cooldown') {
+                    // Skip trimming while session is working (busy/retry)
+                    const status = get().sessionStatus?.get(sessionId);
+                    if (status?.type === 'busy' || status?.type === 'retry') {
                         return;
                     }
                     return useMessageStore.getState().trimToViewportWindow(sessionId, targetSize, currentSessionId || undefined);

packages/ui/src/stores/useUIStore.ts

@@ -34,6 +34,8 @@ interface UIStore {
   isCommandPaletteOpen: boolean;
   isHelpDialogOpen: boolean;
   isAboutDialogOpen: boolean;
+  isOpenCodeStatusDialogOpen: boolean;
+  openCodeStatusText: string;
   isSessionCreateDialogOpen: boolean;
   isSettingsDialogOpen: boolean;
   isModelSelectorOpen: boolean;
@@ -89,6 +91,8 @@ interface UIStore {
   toggleHelpDialog: () => void;
   setHelpDialogOpen: (open: boolean) => void;
   setAboutDialogOpen: (open: boolean) => void;
+  setOpenCodeStatusDialogOpen: (open: boolean) => void;
+  setOpenCodeStatusText: (text: string) => void;
   setSessionCreateDialogOpen: (open: boolean) => void;
   setSettingsDialogOpen: (open: boolean) => void;
   setModelSelectorOpen: (open: boolean) => void;
@@ -133,6 +137,7 @@ interface UIStore {
   openMultiRunLauncherWithPrompt: (prompt: string) => void;
 }
 
+
 export const useUIStore = create<UIStore>()(
   devtools(
     persist(
@@ -154,6 +159,8 @@ export const useUIStore = create<UIStore>()(
         isCommandPaletteOpen: false,
         isHelpDialogOpen: false,
         isAboutDialogOpen: false,
+        isOpenCodeStatusDialogOpen: false,
+        openCodeStatusText: '',
         isSessionCreateDialogOpen: false,
         isSettingsDialogOpen: false,
         isModelSelectorOpen: false,
@@ -336,6 +343,14 @@ export const useUIStore = create<UIStore>()(
           set({ isAboutDialogOpen: open });
         },
 
+        setOpenCodeStatusDialogOpen: (open) => {
+          set({ isOpenCodeStatusDialogOpen: open });
+        },
+
+        setOpenCodeStatusText: (text) => {
+          set({ openCodeStatusText: text });
+        },
+
         setSessionCreateDialogOpen: (open) => {
           set({ isSessionCreateDialogOpen: open });
         },

packages/ui/src/stores/useUpdateStore.ts

@@ -4,7 +4,8 @@ import {
   checkForDesktopUpdates,
   downloadDesktopUpdate,
   restartToApplyUpdate,
-  isDesktopRuntime,
+  isDesktopLocalOriginActive,
+  isTauriShell,
   isWebRuntime,
 } from '@/lib/desktop';
 
@@ -55,7 +56,11 @@ async function checkForWebUpdates(): Promise<UpdateInfo | null> {
 }
 
 function detectRuntimeType(): 'desktop' | 'web' | 'vscode' | null {
-  if (isDesktopRuntime()) return 'desktop';
+  if (isTauriShell()) {
+    // Only use Tauri updater when we're on the local instance.
+    // When viewing a remote host inside the desktop shell, treat update as web update.
+    return isDesktopLocalOriginActive() ? 'desktop' : 'web';
+  }
   if (isWebRuntime()) return 'web';
   return null;
 }
@@ -115,9 +120,12 @@ export const useUpdateStore = create<UpdateStore>()((set, get) => ({
     set({ downloading: true, error: null, progress: null });
 
     try {
-      await downloadDesktopUpdate((progress) => {
+      const ok = await downloadDesktopUpdate((progress) => {
         set({ progress });
       });
+      if (!ok) {
+        throw new Error('Desktop update only works on Local instance');
+      }
       set({ downloading: false, downloaded: true });
     } catch (error) {
       set({
@@ -135,7 +143,10 @@ export const useUpdateStore = create<UpdateStore>()((set, get) => ({
     }
 
     try {
-      await restartToApplyUpdate();
+      const ok = await restartToApplyUpdate();
+      if (!ok) {
+        throw new Error('Desktop restart only works on Local instance');
+      }
     } catch (error) {
       set({
         error: error instanceof Error ? error.message : 'Failed to restart',

packages/ui/src/stores/utils/streamDebug.ts

@@ -6,3 +6,12 @@ export const streamDebugEnabled = (): boolean => {
         return false;
     }
 };
+
+export const sessionStatusDebugEnabled = (): boolean => {
+    if (typeof window === 'undefined') return false;
+    try {
+        return window.localStorage.getItem('openchamber_session_status_debug') === '1';
+    } catch {
+        return false;
+    }
+};