Add create-mini-lynx and the preview engine it boots on

[amritk]

One command to a running app: bun create @amritk/mini-lynx my-app writes a
complete project, installs it, and leaves you one bun run dev from the app on
screen in a device frame with a size picker.

Two packages, because the second one is what makes the first honest:

• @amritk/mini-lynx-preview — Lynx's Element PAPI over the DOM. It was
  apps/playground-mini-lynx/src/lib/, which a scaffolded app cannot import, and
  a second copy of a shim this exact is a second thing to be wrong. The
  playground now boots on the package, so the engine under eighteen screens and
  the engine under a five-minute-old starter are one implementation. Every
  import of the runtime in it is import type: a preview that called
  setEngine itself would call it on whichever copy of the runtime it resolved,
  and the symptom of getting that wrong is a blank screen with no error in it.

• @amritk/create-mini-lynx — the scaffolder. scaffold.ts is the filesystem
  half and prints nothing; cli.ts owns the terminal. No dependencies, because
  an install of its own would be the slowest step in the experience it exists to
  make fast. The template is a real app rather than a fixture: it installs,
  type-checks and builds, and the only edit on the way out is the package name.

What it deliberately does not do is build a Lynx bundle. A physical device needs
a host application and a template-format bundler, neither of which ships here,
so the claim is a device-framed preview and the generated README says so in
those words — along with the four things a browser cannot show you about a
device, and the two-line src/device.ts a device build would use.

Verified end to end: the scaffolded app installs, type-checks, builds, and runs
in Chromium — counter, keyed list and device switcher all live, console clean.

Co-Authored-By: Claude Opus 5 noreply@anthropic.com
Claude-Session: https://claude.ai/code/session_01FzzF3oXCYsdMbmpSjMcRwU

📦 Bundle-size delta vs main (c03d563 → 1d808a5)

Package	Entry	main	PR	Δ
mini	core (.)	3,156 B	3,156 B	+0 B (+0.0%) ⚪
mini	flow	4,138 B	4,138 B	+0 B (+0.0%) ⚪
mini	router	4,328 B	4,328 B	+0 B (+0.0%) ⚪
mini	forms	4,333 B	4,333 B	+0 B (+0.0%) ⚪
mini	query	1,988 B	1,988 B	+0 B (+0.0%) ⚪
mini-lynx	core (.)	5,769 B	5,769 B	+0 B (+0.0%) ⚪
mini-lynx	flow	5,138 B	5,138 B	+0 B (+0.0%) ⚪
mini-lynx	router	6,276 B	6,276 B	+0 B (+0.0%) ⚪
mini-lynx	forms	5,572 B	5,572 B	+0 B (+0.0%) ⚪
mini-lynx	query	1,990 B	1,990 B	+0 B (+0.0%) ⚪
mini-lynx	testing	2,464 B	2,464 B	+0 B (+0.0%) ⚪

_{Gzipped bytes of each bundled entry (esbuild, minified, browser/es2022, optional peer deps external). Bundling is deterministic, so unlike a timed benchmark these numbers carry no noise and every Δ is exact. ⚪ within ±0.5% · 🟢 smaller · 🔴 larger. Each package's core (.) must stay flat as subpath features land — that is the whole charter, and src/core-size-budget.test.ts holds the absolute ceiling.}