Scaffold CommiTea: yarn workspaces, Electron shell, core label schema, design system

- apps/desktop: electron-vite + React + Tailwind mapped onto design tokens
  (preflight off; tokens/base.css owns the reset); boots to a Reginald
  placeholder proving fonts/tokens/core wiring
- packages/core: pure TS; gitea label schema (est/*, p/*, deadline/hard)
  with pessimistic conflict resolution + 15 unit tests
- docs/design: full design handoff (tokens, 16 component contracts,
  interactive 14-screen prototype, Reginald voice rules)
- docs/PLAN.md: product plan (purity rule, pm-state repo, deterministic
  scheduler + Monte Carlo, directive log)
- Deliberate deviation from novelpad stack: no ElectricSQL/PGlite — local
  store is a rebuildable cache over gitea REST/webhooks (better-sqlite3
  in main process, arriving in P1)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/desktop/src/main/index.ts

@@ -0,0 +1,44 @@
+import { join } from 'node:path'
+
+import { BrowserWindow, app, shell } from 'electron'
+
+function createWindow(): void {
+  const win = new BrowserWindow({
+    width: 1440,
+    height: 900,
+    minWidth: 1080,
+    minHeight: 700,
+    show: false,
+    autoHideMenuBar: true,
+    backgroundColor: '#F0F4F0',
+    webPreferences: {
+      preload: join(import.meta.dirname, '../preload/index.mjs'),
+      sandbox: false,
+    },
+  })
+
+  win.on('ready-to-show', () => win.show())
+
+  win.webContents.setWindowOpenHandler(({ url }) => {
+    void shell.openExternal(url)
+    return { action: 'deny' }
+  })
+
+  if (process.env.ELECTRON_RENDERER_URL) {
+    void win.loadURL(process.env.ELECTRON_RENDERER_URL)
+  } else {
+    void win.loadFile(join(import.meta.dirname, '../renderer/index.html'))
+  }
+}
+
+void app.whenReady().then(() => {
+  createWindow()
+
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows().length === 0) createWindow()
+  })
+})
+
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') app.quit()
+})