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/components/ui/tooltip.tsx

@@ -0,0 +1,30 @@
+'use client';
+
+import * as React from 'react';
+import * as TooltipPrimitive from '@radix-ui/react-tooltip';
+
+import { cn } from '@/lib/utils';
+
+const TooltipProvider = TooltipPrimitive.Provider;
+
+const Tooltip = TooltipPrimitive.Root;
+
+const TooltipTrigger = TooltipPrimitive.Trigger;
+
+const TooltipContent = React.forwardRef<
+  React.ComponentRef<typeof TooltipPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof TooltipPrimitive.Content>
+>(({ className, sideOffset = 4, ...props }, ref) => (
+  <TooltipPrimitive.Content
+    ref={ref}
+    sideOffset={sideOffset}
+    className={cn(
+      'z-50 overflow-hidden rounded-md border border-border bg-popover px-3 py-1.5 text-sm text-popover-foreground shadow-md animate-in fade-in-0 zoom-in-95 data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=closed]:zoom-out-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2',
+      className
+    )}
+    {...props}
+  />
+));
+TooltipContent.displayName = TooltipPrimitive.Content.displayName;
+
+export { Tooltip, TooltipTrigger, TooltipContent, TooltipProvider };