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/components/ui/sheet.tsx

@@ -0,0 +1,138 @@
+"use client"
+
+import * as React from "react"
+import { Dialog as SheetPrimitive } from "@base-ui/react/dialog"
+
+import { cn } from "~/lib/utils"
+import { Button } from "~/components/ui/button"
+import { XIcon } from "lucide-react"
+
+function Sheet({ ...props }: SheetPrimitive.Root.Props) {
+  return <SheetPrimitive.Root data-slot="sheet" {...props} />
+}
+
+function SheetTrigger({ ...props }: SheetPrimitive.Trigger.Props) {
+  return <SheetPrimitive.Trigger data-slot="sheet-trigger" {...props} />
+}
+
+function SheetClose({ ...props }: SheetPrimitive.Close.Props) {
+  return <SheetPrimitive.Close data-slot="sheet-close" {...props} />
+}
+
+function SheetPortal({ ...props }: SheetPrimitive.Portal.Props) {
+  return <SheetPrimitive.Portal data-slot="sheet-portal" {...props} />
+}
+
+function SheetOverlay({ className, ...props }: SheetPrimitive.Backdrop.Props) {
+  return (
+    <SheetPrimitive.Backdrop
+      data-slot="sheet-overlay"
+      className={cn(
+        "fixed inset-0 z-50 bg-black/10 transition-opacity duration-fast data-ending-style:opacity-0 data-starting-style:opacity-0 supports-backdrop-filter:backdrop-blur-xs",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function SheetContent({
+  className,
+  children,
+  side = "right",
+  showCloseButton = true,
+  ...props
+}: SheetPrimitive.Popup.Props & {
+  side?: "top" | "right" | "bottom" | "left"
+  showCloseButton?: boolean
+}) {
+  return (
+    <SheetPortal>
+      <SheetOverlay />
+      <SheetPrimitive.Popup
+        data-slot="sheet-content"
+        data-side={side}
+        className={cn(
+          "fixed z-50 flex flex-col gap-4 bg-popover bg-clip-padding text-sm text-popover-foreground shadow-lg transition duration-base ease-in-out data-ending-style:opacity-0 data-starting-style:opacity-0 data-[side=bottom]:inset-x-0 data-[side=bottom]:bottom-0 data-[side=bottom]:h-auto data-[side=bottom]:border-t data-[side=bottom]:data-ending-style:translate-y-[2.5rem] data-[side=bottom]:data-starting-style:translate-y-[2.5rem] data-[side=left]:inset-y-0 data-[side=left]:left-0 data-[side=left]:h-full data-[side=left]:w-3/4 data-[side=left]:border-r data-[side=left]:data-ending-style:translate-x-[-2.5rem] data-[side=left]:data-starting-style:translate-x-[-2.5rem] data-[side=right]:inset-y-0 data-[side=right]:right-0 data-[side=right]:h-full data-[side=right]:w-3/4 data-[side=right]:border-l data-[side=right]:data-ending-style:translate-x-[2.5rem] data-[side=right]:data-starting-style:translate-x-[2.5rem] data-[side=top]:inset-x-0 data-[side=top]:top-0 data-[side=top]:h-auto data-[side=top]:border-b data-[side=top]:data-ending-style:translate-y-[-2.5rem] data-[side=top]:data-starting-style:translate-y-[-2.5rem] data-[side=left]:sm:max-w-sm data-[side=right]:sm:max-w-sm",
+          className
+        )}
+        {...props}
+      >
+        {children}
+        {showCloseButton && (
+          <SheetPrimitive.Close
+            data-slot="sheet-close"
+            render={
+              <Button
+                variant="ghost"
+                className="absolute top-3 right-3"
+                size="icon-sm"
+              />
+            }
+          >
+            <XIcon
+            />
+            <span className="sr-only">Close</span>
+          </SheetPrimitive.Close>
+        )}
+      </SheetPrimitive.Popup>
+    </SheetPortal>
+  )
+}
+
+function SheetHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sheet-header"
+      className={cn("flex flex-col gap-0.5 p-4", className)}
+      {...props}
+    />
+  )
+}
+
+function SheetFooter({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sheet-footer"
+      className={cn("mt-auto flex flex-col gap-2 p-4", className)}
+      {...props}
+    />
+  )
+}
+
+function SheetTitle({ className, ...props }: SheetPrimitive.Title.Props) {
+  return (
+    <SheetPrimitive.Title
+      data-slot="sheet-title"
+      className={cn(
+        "font-heading text-base font-medium text-foreground",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function SheetDescription({
+  className,
+  ...props
+}: SheetPrimitive.Description.Props) {
+  return (
+    <SheetPrimitive.Description
+      data-slot="sheet-description"
+      className={cn("text-sm text-muted-foreground", className)}
+      {...props}
+    />
+  )
+}
+
+export {
+  Sheet,
+  SheetTrigger,
+  SheetClose,
+  SheetContent,
+  SheetHeader,
+  SheetFooter,
+  SheetTitle,
+  SheetDescription,
+}