feat: initialize AIUI monorepo with project rules and core types

Foundation for the next-generation AI content surface UI:
- 16 Cursor rules files covering philosophy, Vue conventions, design system,
  content surfaces, plugin system, AI integration, renderers, security,
  Bitcoin-only policy, dev/prod modes, accessibility, performance, animation,
  mobile UX, and git workflow
- pnpm workspaces + Turborepo monorepo (@aiui/core, @aiui/app)
- Vue 3 + Vite + TypeScript + Tailwind CSS 4
- Core type system: plugins, renderers, messages, content blocks
- Plugin registry with renderer registration
- 50 mock film fixtures with search/filter utilities
- App shell with chat page layout
- Environment config templates

Made-with: Cursor

packages/core/src/env.d.ts

@@ -0,0 +1,7 @@
+/// <reference types="vite/client" />
+
+declare module '*.vue' {
+  import type { DefineComponent } from 'vue'
+  const component: DefineComponent<object, object, unknown>
+  export default component
+}