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>

docs/design/components/core/Tabs.d-ts.txt

@@ -0,0 +1,19 @@
+/**
+ * Underline tabs for view switching (Board / Gantt / Dependencies).
+ */
+export interface TabItem {
+  id: string;
+  label: string;
+  /** Lucide icon name */
+  icon?: string;
+  /** Mono count rendered after the label */
+  count?: number;
+}
+export interface TabsProps {
+  items: TabItem[];
+  /** id of the active tab */
+  active: string;
+  onChange?: (id: string) => void;
+  style?: React.CSSProperties;
+}
+export declare function Tabs(props: TabsProps): JSX.Element;