feat(bankai): Phase 4 follow-ups — css convention, live titles, prerender, HTTP/2, size budget

- style.css convention: <entry dir>/style.css is imported by the virtual
  client entry (CSS is a client concern; server code never sees it — the
  v8 answer to sheetify), extracted and hashed by Vite, stylesheet-linked
  in the head and preloaded via Early Hints. Counter example styled.
- SSR <title> from state: the server reads the first stream chunk before
  writing the head, by which point stores and the first render slice have
  run — DOMTitleChange emits land in the document title. Counter emits.
- bankai build --prerender /,/about renders routes through the same
  toStream path to static <route>/index.html (precompressed, precached
  by the service worker, served with Early Hints).
- bankai serve --h2: HTTP/2 with a generated local cert (openssl,
  cached; allowHTTP1) — browsers only act on Early Hints over h2/h3.
  Tested with a real h2 client observing the 103 interim response.
- npm run size: the framework wire-size budget, enforced in CI. Whole
  framework (core + html engine + morph + hydrate) is 7.97 kB min+gzip /
  7.15 kB brotli; budget 8.5 kB with the v7 '4kb' context documented
  (that number excluded the html engine, which lived in the browserify
  transform).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014NgfSjHE11oFpoSnLVKLXd

packages/bankai/cli.js

@@ -9,6 +9,9 @@
 //   bankai inspect         size report for the built output
 //
 // options: --port <n>  --out <dir>  --title <text>
+//          --prerender </,/about>  (build: comma-separated routes)
+//          --h2                    (serve: HTTP/2 + local cert, so
+//                                   browsers act on the Early Hints)
 
 import { parseArgs } from 'node:util'
 
@@ -17,7 +20,9 @@ const { values, positionals } = parseArgs({
   options: {
     port: { type: 'string' },
     out: { type: 'string', default: 'dist' },
-    title: { type: 'string', default: 'choo' }
+    title: { type: 'string', default: 'choo' },
+    prerender: { type: 'string' },
+    h2: { type: 'boolean', default: false }
   }
 })
 
@@ -33,11 +38,13 @@ try {
   } else if (command === 'build') {
     requireEntry(entry)
     const { default: build } = await import('./lib/build.js')
-    const { outDir, compressed } = await build({ entry, outDir: values.out, title: values.title })
-    console.log(`bankai: built to ${outDir} (${compressed} asset(s) precompressed) — bankai serve to run it`)
+    const prerender = values.prerender ? values.prerender.split(',').map((r) => r.trim()).filter(Boolean) : []
+    const { outDir, compressed, prerendered } = await build({ entry, outDir: values.out, title: values.title, prerender })
+    const extra = prerendered.length ? `, ${prerendered.length} route(s) prerendered` : ''
+    console.log(`bankai: built to ${outDir} (${compressed} asset(s) precompressed${extra}) — bankai serve to run it`)
   } else if (command === 'serve') {
     const { default: serve } = await import('./lib/serve.js')
-    const { origin } = await serve({ outDir: values.out, port })
+    const { origin } = await serve({ outDir: values.out, port, h2: values.h2 })
     console.log(`bankai: production server on ${origin}`)
   } else if (command === 'inspect') {
     const { default: inspect } = await import('./lib/inspect.js')