refactor(sidebar): extract typed app/sidebar architecture and split Sidebar into modular components

- Replace `src/App.jsx` with `src/App.tsx` and move route-level UI orchestration into `src/components/app/AppContent.tsx`.
  This separates provider/bootstrap concerns from runtime app layout logic, keeps route definitions minimal, and improves readability of the root app entry.

- Introduce `src/hooks/useProjectsState.ts` to centralize project/session/sidebar state management previously embedded in `App.jsx`.
  This keeps the existing behavior for:
  project loading,
  Cursor session hydration,
  WebSocket `loading_progress` handling,
  additive-update protection for active sessions,
  URL-based session selection,
  sidebar refresh/delete/new-session flows.
  The hook now exposes a typed `sidebarSharedProps` contract and typed handlers used by `AppContent`.

- Introduce `src/hooks/useSessionProtection.ts` for active/processing session lifecycle logic.
  This preserves session-protection behavior while isolating `activeSessions`, `processingSessions`, and temporary-session replacement into a dedicated reusable hook.

- Replace monolithic `src/components/Sidebar.jsx` with typed `src/components/Sidebar.tsx` as a thin orchestrator.
  `Sidebar.tsx` now focuses on wiring controller state/actions, modal visibility, collapsed mode, and version modal behavior instead of rendering every UI branch inline.

- Add `src/hooks/useSidebarController.ts` to encapsulate sidebar interaction/state logic.
  This includes expand/collapse state, inline project/session editing state, project starring/sorting/filtering, lazy session pagination, delete confirmations, rename/delete actions, refresh state, and mobile touch click handling.

- Add strongly typed sidebar domain models in `src/components/sidebar/types.ts` and move sidebar-derived helpers into `src/components/sidebar/utils.ts`.
  Utility coverage now includes:
  session provider normalization,
  session view-model creation (name/time/activity/message count),
  project sorting/filtering,
  task indicator status derivation,
  starred-project persistence and readbacks.

- Split sidebar rendering into focused components under `src/components/sidebar/`:
  `SidebarContent.tsx` for top-level sidebar layout composition.
  `SidebarProjectList.tsx` for project-state branching and project iteration.
  `SidebarProjectsState.tsx` for loading/empty/no-search-result placeholders.
  `SidebarProjectItem.tsx` for per-project desktop/mobile header rendering and actions.
  `SidebarProjectSessions.tsx` for expanded session area, skeletons, pagination, and new-session controls.
  `SidebarSessionItem.tsx` for per-session desktop/mobile item rendering and session actions.
  `SessionProviderIcon.tsx` for provider icon normalization.
  `SidebarHeader.tsx`, `SidebarFooter.tsx`, `SidebarCollapsed.tsx`, and `SidebarModals.tsx` as dedicated typed UI surfaces.
  This keeps rendering responsibilities local and significantly improves traceability.

- Convert shared UI primitives from JSX to TSX:
  `src/components/ui/button.tsx`,
  `src/components/ui/input.tsx`,
  `src/components/ui/badge.tsx`,
  `src/components/ui/scroll-area.tsx`.
  These now provide typed props/variants (`forwardRef` where appropriate) while preserving existing class/behavior.

- Add shared app typings in `src/types/app.ts` for projects/sessions/websocket/loading contracts used by new hooks/components.

- Add global window declarations in `src/types/global.d.ts` for `__ROUTER_BASENAME__`, `refreshProjects`, and `openSettings`, removing implicit `any` usage for global integration points.

- Update `src/main.jsx` to import `App.tsx` and keep app bootstrap consistent with the TS migration.

- Update `src/components/QuickSettingsPanel.jsx` to self-resolve mobile state via `useDeviceSettings` (remove `isMobile` prop dependency), and update `src/components/ChatInterface.jsx` to render `QuickSettingsPanel` directly.
  This reduces prop drilling and keeps quick settings colocated with chat UI concerns.

src/types/global.d.ts

@@ -0,0 +1,9 @@
+export {};
+
+declare global {
+  interface Window {
+    __ROUTER_BASENAME__?: string;
+    refreshProjects?: () => void | Promise<void>;
+    openSettings?: (tab?: string) => void;
+  }
+}