fix(desktop): honor default project directory for new sessions (#43234)

* fix(desktop): honor default project directory for new sessions

The Settings picker persisted project-dir.json but the renderer kept
seeding new chats from sticky localStorage home. Prefer the configured
default on boot and session.create, pin TERMINAL_CWD at backend spawn,
and reject packaged install-dir paths that regressed after #37536.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(desktop): address review on default project dir PR

Add workspace cwd precedence tests, extract isPackagedInstallPath for
platform test coverage, and stop rewriting live $currentCwd when a
session is already active (cache-only until the next new chat).

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/desktop/src/app/session/hooks/use-session-actions.ts

@@ -20,6 +20,7 @@ import {
   $sessions,
   $yoloActive,
   getRememberedWorkspaceCwd,
+  workspaceCwdForNewSession,
   sessionPinId,
   setActiveSessionId,
   setAwaitingResponse,
@@ -311,8 +312,9 @@ export function useSessionActions({
       })
       setSessionStartedAt(null)
       setTurnStartedAt(null)
-      // New chats inherit the current workspace.
-      setCurrentCwd(getRememberedWorkspaceCwd())
+      // New chats start in the configured default project dir when set,
+      // otherwise the sticky last-used workspace (PR #37586).
+      setCurrentCwd(workspaceCwdForNewSession())
       setCurrentBranch('')
       clearComposerDraft()
       clearComposerAttachments()
@@ -333,7 +335,7 @@ export function useSessionActions({
         // Route the new chat to the chosen profile's backend (null = primary,
         // so single-profile users are unaffected).
         await ensureGatewayProfile($newChatProfile.get())
-        const cwd = $currentCwd.get().trim() || getRememberedWorkspaceCwd()
+        const cwd = $currentCwd.get().trim() || workspaceCwdForNewSession()
         // Pass the owning profile so a new chat under a non-launch profile (global
         // remote mode) builds its agent + persists against THAT profile's home/db.
         const newChatProfile = $newChatProfile.get()