feat(chats): add managed projectless chat sessions

Create projectless chat sessions under a managed, date-scoped Chats directory and clean abandoned or deleted session folders.

Add Chats to sidebar state, startup cache, shared context, and Electron Mini Chat while keeping VS Code project-only. Resolve managed chat directories to one server-side memory owner and document the runtime contracts.

packages/ui/src/components/layout/RightSidebarTabs.tsx

@@ -5,6 +5,9 @@ import { useGitStore } from '@/stores/useGitStore';
 import { useProjectsStore } from '@/stores/useProjectsStore';
 import { useDirectoryStore } from '@/stores/useDirectoryStore';
 import { formatDirectoryName } from '@/lib/utils';
+import { useSessionUIStore } from '@/sync/session-ui-store';
+import { CHAT_DRAFT_PROJECT_ID, getChatsRootForHome, getChatsRootFromDirectory, isChatDirectoryPath } from '@/lib/chatDirectories';
+import { useI18n } from '@/lib/i18n';
 
 export const ProjectContextPanel: React.FC<{
   onActionComplete?: () => void;
@@ -13,16 +16,28 @@ export const ProjectContextPanel: React.FC<{
   const activeProjectId = useProjectsStore((state) => state.activeProjectId);
   const projects = useProjectsStore((state) => state.projects);
   const homeDirectory = useDirectoryStore((state) => state.homeDirectory);
+  const { t } = useI18n();
   const gitDirectories = useGitStore((state) => state.directories);
+  const isChatContext = useSessionUIStore((state) => (
+    state.newSessionDraft.open
+      ? state.newSessionDraft.target === 'chat'
+      : isChatDirectoryPath(state.currentSessionDirectory)
+  ));
+  const chatSessionDirectory = useSessionUIStore((state) => state.currentSessionDirectory);
+  const chatsRoot = getChatsRootFromDirectory(chatSessionDirectory) ?? getChatsRootForHome(homeDirectory);
 
   const activeProject = React.useMemo(() => {
+    if (isChatContext) return null;
     if (activeProjectId) {
       return projects.find((project) => project.id === activeProjectId) ?? projects[0] ?? null;
     }
     return projects[0] ?? null;
-  }, [activeProjectId, projects]);
+  }, [activeProjectId, isChatContext, projects]);
 
   const projectRef = React.useMemo(() => {
+    if (isChatContext && chatsRoot) {
+      return { id: CHAT_DRAFT_PROJECT_ID, path: chatsRoot };
+    }
     if (!activeProject) {
       return null;
     }
@@ -30,16 +45,17 @@ export const ProjectContextPanel: React.FC<{
       id: activeProject.id,
       path: activeProject.path,
     };
-  }, [activeProject]);
+  }, [activeProject, chatsRoot, isChatContext]);
 
   const projectLabel = React.useMemo(() => {
+    if (isChatContext) return t('sessions.sidebar.activity.chatsTitle');
     if (!activeProject) {
       return null;
     }
     return activeProject.label?.trim()
       || formatDirectoryName(activeProject.path, homeDirectory)
       || activeProject.path;
-  }, [activeProject, homeDirectory]);
+  }, [activeProject, homeDirectory, isChatContext, t]);
 
   const canCreateWorktree = React.useMemo(() => {
     if (!activeProject) {