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/vite.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from "vite";
+
+// Builds into ../web, which `crows serve` hosts. `npm run dev` proxies the API to a running server.
+export default defineConfig({
+  build: { outDir: "../web", emptyOutDir: true },
+  server: { proxy: { "/api": "http://127.0.0.1:8080" } },
+});