feat: initial commit — crema-app-aifirst-template

Hybrid traditional + AI-first webapp scaffold. Sibling to crema-app-template,
adds the AI assistant surface, command bus, scripts dialog, and virtual
cursor.

What's pre-wired:
- 6 routes: Overview, Resources, Activity, Assistant, Library, Settings
- Collapsible rail + appbar + avatar dropdown shell (template code, not a lib)
- Mobile sheet at <md
- /assistant: streaming chat via @crema/llm-ui, mock fallback, model selector,
  token meter, retry probe, stop-while-streaming, persistent UI Control toggle
- /settings: editable LM Studio endpoint + context window + response cap, with
  test-connection button
- Markdown rendering for assistant replies; ```action``` blocks rendered as a
  small "Ran N actions" pill
- ⌘⇧P script runner dialog + Play icon in the appbar
- Two demo scripts in public/scripts/
- mightypix theme as default, scoped via <AppShell theme="mightypix">

Libs wired in tsconfig + app.css:
- @crema/action-bus (the bus, parser, runner, cursor, provider, ws, llm-bridge)
- @crema/llm-ui, @crema/chat-ui, @crema/aifirst-ui, @crema/notification-ui
- lib-theme-mightypix

Docs:
- README.md — pitch + quick start + structure
- docs/AI_FIRST.md — full system tour (data-action contract, bus, DSL, scripts,
  cursor, LLM integration)
- app/components/layout/THEME_CONTRACT.md — every CSS variable a theme must declare
- CLAUDE.md — orientation for an LLM working in the repo

Genericized from comfy-cloud (the original prototype):
- Brand defaults to "App" / Sparkles icon (override via app/lib/identity.ts)
- User defaults to a stub (swap useUser() for real auth)
- localStorage namespace is "crema.*" (was "comfy.*")

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/hooks/use-mobile.ts

@@ -0,0 +1,15 @@
+import * as React from "react"
+
+const MOBILE_BREAKPOINT = 768
+
+export function useIsMobile() {
+  const [isMobile, setIsMobile] = React.useState<boolean | undefined>(undefined)
+  React.useEffect(() => {
+    const mql = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`)
+    const onChange = () => setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
+    mql.addEventListener("change", onChange)
+    setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
+    return () => mql.removeEventListener("change", onChange)
+  }, [])
+  return !!isMobile
+}