T1/Phase 1: scaffold Vite SPA + Hono API + Bun worker

- apps/web: Vite + React 19 + TanStack Router/Query + shadcn/ui
   - apps/api: Hono + Bun on :3001 with /api/health, /api/auth/*, /mcp stubs
   - apps/worker: Bun worker stub, DB connection, graceful SIGTERM
   - apps/web-legacy/: old Next.js code moved aside (preserved for T2-T8 reference)
   - Dockerfiles: api (Bun), worker (Bun), spa (multi-stage Caddy)
   - Caddyfile: serves dist + reverse-proxies /api/* + /mcp to api
   - docker-compose.yml: 4-service target (api, spa, db, worker)
   - packages/db/src/client.ts: shared Drizzle client for api + worker
   - db/client.ts: root-level alias for convenience

   Parent: t_e1cbd87d -> t_24c9c3fd (T0)

apps/web-legacy/types/react-calendar-heatmap.d.ts

@@ -0,0 +1,35 @@
+declare module 'react-calendar-heatmap' {
+  import { ComponentType } from 'react';
+
+  interface HeatmapValue {
+    date: Date | string;
+    count: number;
+  }
+
+  interface ReactCalendarHeatmapProps {
+    startDate: Date | string;
+    endDate: Date | string;
+    values: HeatmapValue[];
+    classForValue?: (value: HeatmapValue | null) => string;
+    tooltipDataAttrs?: (value: HeatmapValue | null) => Record<string, string | number> | null;
+    showWeekdayLabels?: boolean;
+    showMonthLabels?: boolean;
+    showOutOfRangeDays?: boolean;
+    numDays?: number;
+    gutterSize?: number;
+    horizontal?: boolean;
+    transformDayElement?: (
+      element: JSX.Element,
+      value: HeatmapValue | null,
+      index: number
+    ) => JSX.Element;
+    monthLabels?: string[] | Record<string, string>;
+    weekdayLabels?: string[];
+    onClick?: (value: HeatmapValue | null) => void;
+    onMouseOver?: (value: HeatmapValue | null, event: React.MouseEvent) => void;
+    onMouseLeave?: (value: HeatmapValue | null, event: React.MouseEvent) => void;
+  }
+
+  const CalendarHeatmap: ComponentType<ReactCalendarHeatmapProps>;
+  export default CalendarHeatmap;
+}