feat(desktop): session hygiene, archive, media streaming + connecting overlay (#37099)

* feat(desktop): session hygiene, archive, media streaming + connecting overlay

Address a batch of desktop feedback:

- Stop leaking empty "Untitled" sessions: the TUI gateway pre-created a DB
  row on every session.create (i.e. every launch/draft). Persist the row
  lazily on first prompt instead, and hide message-less rows in the sidebar.
- Archive/hide sessions: new `archived` column + set_session_archived, web
  API (`?archived=` + PATCH archived), Ctrl/⌘-click and a context-menu item
  in the sidebar, and an "Archived Chats" settings panel to restore/delete.
- Videos load via a streaming `hermes-media://` protocol instead of capped,
  in-memory data URLs (16 MB limit) — bypasses the cap and supports seeking.
- Background-process completions route to the session that launched them:
  the completion event now carries session_key and each poller only consumes
  its own.
- Sidebar: "Group by workspace" toggle is always visible; each workspace
  group gets a "+" to start a session in that directory; "New agent"/"Agents"
  relabeled to "New session"/"Sessions".
- New gateway connecting overlay (ascii decode → fade out) replacing the bare
  skeleton/"starting gateway" state.

* fix(desktop): bail connecting overlay on boot error

The shownRef latch kept the connecting overlay mounted behind
BootFailureOverlay after a hard boot failure. Return null on boot.error
so the failure recovery surface fully owns the screen.

* fix(desktop): address Copilot review

- /api/sessions: validate `archived` (400 on unknown) and return `archived`
  as a JSON boolean instead of SQLite's 0/1.
- PATCH /api/sessions/{id}: 400 (not a misleading 404) when the body has no
  updatable fields; stop conflating a no-op with "not found".
- hermes-media protocol: drop `bypassCSP` — streaming only needs
  secure/standard/stream/supportFetchAPI.
- Sidebar workspace header: split the toggle and the "+" into sibling buttons
  so we no longer nest interactive elements inside a <button>.

* fix(desktop): address Copilot re-review

- hermes-media protocol: restrict streaming to an audio/video extension
  allowlist (415 otherwise) so it can't be used to read arbitrary local files.
- Connecting overlay: use z-[1200] instead of the non-standard z-1200 utility.

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

apps/desktop/src/app/desktop-controller.tsx

@@ -6,6 +6,7 @@ import { Navigate, Route, Routes, useLocation, useNavigate, useParams } from 're
 import { BootFailureOverlay } from '@/components/boot-failure-overlay'
 import { DesktopInstallOverlay } from '@/components/desktop-install-overlay'
 import { DesktopOnboardingOverlay } from '@/components/desktop-onboarding-overlay'
+import { GatewayConnectingOverlay } from '@/components/gateway-connecting-overlay'
 import { Pane, PaneMain } from '@/components/pane-shell'
 import { useSkinCommand } from '@/themes/use-skin-command'
 
@@ -33,6 +34,8 @@ import {
   $selectedStoredSessionId,
   setAwaitingResponse,
   setBusy,
+  setCurrentBranch,
+  setCurrentCwd,
   setCurrentModel,
   setCurrentProvider,
   setMessages,
@@ -122,6 +125,7 @@ export function DesktopController() {
     settingsOpen,
     toggleCommandCenter
   } = useOverlayRouting()
+
   const terminalTakeoverActive = chatOpen && terminalTakeover
 
   const titlebarToolGroups = useGroupRegistry<TitlebarTool>()
@@ -192,7 +196,10 @@ export function DesktopController() {
 
     try {
       const limit = $sessionsLimit.get()
-      const result = await listSessions(limit)
+      // Require at least one message so abandoned/empty "Untitled" drafts (one
+      // was created per TUI/desktop launch before the lazy-create fix) don't
+      // clutter the sidebar.
+      const result = await listSessions(limit, 1)
 
       if (refreshSessionsRequestRef.current === requestId) {
         setSessions(result.sessions)
@@ -324,6 +331,7 @@ export function DesktopController() {
   })
 
   const {
+    archiveSession,
     branchCurrentSession,
     createBackendSessionForSend,
     openSettings,
@@ -392,6 +400,29 @@ export function DesktopController() {
     [branchCurrentSession, refreshSessions]
   )
 
+  const startSessionInWorkspace = useCallback(
+    (path: null | string) => {
+      startFreshSessionDraft()
+
+      const target = path?.trim()
+
+      if (!target) {
+        return
+      }
+
+      // The next message creates the backend session in $currentCwd, so seed
+      // it (and the branch) from the workspace the user clicked the + on.
+      setCurrentCwd(target)
+      void requestGateway<{ branch?: string; cwd?: string }>('config.get', { key: 'project', cwd: target })
+        .then(info => {
+          setCurrentCwd(info.cwd || target)
+          setCurrentBranch(info.branch || '')
+        })
+        .catch(() => undefined)
+    },
+    [requestGateway, startFreshSessionDraft]
+  )
+
   const handleSkinCommand = useSkinCommand()
 
   const { cancelRun, editMessage, handleThreadMessagesChange, reloadFromMessage, submitText, transcribeVoiceAudio } =
@@ -461,9 +492,11 @@ export function DesktopController() {
   const sidebar = (
     <ChatSidebar
       currentView={currentView}
+      onArchiveSession={sessionId => void archiveSession(sessionId)}
       onDeleteSession={sessionId => void removeSession(sessionId)}
       onLoadMoreSessions={loadMoreSessions}
       onNavigate={selectSidebarItem}
+      onNewSessionInWorkspace={startSessionInWorkspace}
       onResumeSession={sessionId => navigate(sessionRoute(sessionId))}
     />
   )
@@ -485,6 +518,7 @@ export function DesktopController() {
       />
       <ModelPickerOverlay gateway={gatewayRef.current || undefined} onSelect={selectModel} />
       <UpdatesOverlay />
+      <GatewayConnectingOverlay />
       <BootFailureOverlay />
 
       {settingsOpen && (
@@ -575,10 +609,10 @@ export function DesktopController() {
       titlebarTools={titlebarToolGroups.flat.right}
     >
       <Pane
+        disabled={terminalTakeoverActive}
         id="chat-sidebar"
         maxWidth={SIDEBAR_MAX_WIDTH}
         minWidth={SIDEBAR_DEFAULT_WIDTH}
-        disabled={terminalTakeoverActive}
         resizable
         side="left"
         width={`${SIDEBAR_DEFAULT_WIDTH}px`}