perf: improve application startup performance

Renderer code splitting:
- Lazy-load 15 components with React.lazy() and Suspense (ChatPane,
  ActivityPanel, SettingsPanel, TerminalPanel, WelcomePane, BottomPanel,
  GitPanel, CommandPalette, CommitComposer, WorkflowPicker, BookmarksPanel,
  SessionSearchPanel, KeyboardShortcutsPanel, DiscoveredToolingModal,
  ProjectSettingsPanel)
- This moves ~1.2 MB of optional dependencies (Lexical, @xyflow/react,
  @xterm/xterm, highlight.js, motion) out of the critical bundle
- Critical bundle reduced from ~1.5 MB to ~759 KB
- Defer JetBrains Mono font load to TerminalPanel (saves ~80 KB at startup)

Main process optimizations:
- Use show: false + ready-to-show on BrowserWindow to eliminate blank flash
- Decouple workspace loading from bootstrap — no longer blocks window, tray,
  and auto-update setup
- Defer sidecar-dependent approval tool pruning to run in background after
  workspace is returned to renderer (removes sidecar spawn from critical path)
- Parallelize independent workspace sync operations (user tooling, project
  tooling, project customization) with Promise.all()

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/components/TerminalPanel.tsx

@@ -3,6 +3,7 @@ import { RotateCcw } from 'lucide-react';
 import { Terminal } from '@xterm/xterm';
 import { FitAddon } from '@xterm/addon-fit';
 import '@xterm/xterm/css/xterm.css';
+import '@fontsource-variable/jetbrains-mono';
 
 import { getElectronApi } from '@renderer/lib/electronApi';
 import type { TerminalSnapshot } from '@shared/domain/terminal';