feat(web): workspace components — ComparePane, Memory page, McpDialog, error boundaries, message-parts

- Add ComparePane.tsx: side-by-side AI response comparison
- Add Memory.tsx: memory management page with CRUD UI
- Add McpPermissionDialog.tsx: MCP tool permission approval dialog
- Add McpResponseDisplay.tsx: MCP response visualization
- Add MessageBoundary.tsx + MessageListErrorBoundary.tsx: error resilience
- Add EmptyState.tsx: contextual empty state component
- Add KeyboardShortcutsDialog.tsx: keyboard shortcut reference
- Add message-parts/: ActionRow, CompactCard, MistakeRecoverySentinel, ReasoningBlock, SendToTerminalMenu, StatsLine, SummaryCard
- Add useDraftPersistence.ts: draft message persistence hook
- Add useTerminals.ts: terminal session management hook
- Add keyboard-shortcuts.ts + tool-utils.ts: shared utilities
- Extend components: ChatInput, MessageBubble, MessageList, Workspace, panes
- Extend hooks: useTerminalSocket, useSessionStream test suite
- Update pages: Home, Project — workspace layout and session flow

apps/web/src/components/message-parts/index.ts

@@ -0,0 +1,7 @@
+export { StatsLine } from './StatsLine';
+export { ActionRow } from './ActionRow';
+export { CompactCard } from './CompactCard';
+export { SummaryCard } from './SummaryCard';
+export { ReasoningBlock } from './ReasoningBlock';
+export { MistakeRecoverySentinel } from './MistakeRecoverySentinel';
+export { SendToTerminalMenu } from './SendToTerminalMenu';