Add web UI with Smokey's crow as the stand-in mascot

- ui/: Vite + plain TypeScript, builds into ./web for `crows serve`
- CrowView mirrors CrowModel in RIVE_CONTRACT.md (pose, trust,
  reactions) so the .riv can replace the SVG later
- Event handling follows the contract's mapping table; server text
  is only ever inserted as text
- Prank: toast plus a send-button cooldown countdown
- art/crow.svg: source art for Rive import

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UQnSw4RRWp8uqpj3nsnnXF

ui/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "strict": true,
+    "noUnusedLocals": true,
+    "noEmit": true,
+    "skipLibCheck": true
+  },
+  "include": ["src"]
+}