refactor: retire the hand-written site

Deletes the pre-Astro pages, scripts, and stylesheets that the migration
replaced, and moves the ones it did not replace out of the way.

Deleted (32 files): app.js, responsive.css, landing.css, rules/app.js,
rules/styles.css, skills/app.js, the ten route index.html files, and the
root hands-on/ copy, which is byte-identical to public/hands-on/ -- the
one the build actually ships.

Moved to legacy/ (12 files): styles.css, full-guide/audit.css,
chapters.css, skills/styles.css, skills-review/styles.css,
skills-review/change-lens.css, and the skills-review/app.js module graph.
These are not dead. The Astro pages import them and the build fails
without them, which the plan had not accounted for. They go to legacy/
rather than src/ because check-tokens.mjs sweeps src, and these files are
full of raw hex and unnamed breakpoints: moving one into src/ should mean
migrating it to tokens in the same change, not adding a scan exclusion.
The prettier, stylelint, and eslint ignore lists that already named these
files at their old paths now name legacy/ instead.

verify.mjs no longer reads app.js. The 102 Portuguese strings were
extracted from its translations.pt object before deletion into
.agents/snapshots/full-guide-pt.json -- a legacy capture, not a snapshot
of the Astro build, so the assertion still compares against an
independent source. The brace-matching helper's assertion is replaced by
one that rejects an empty snapshot entry, without which trimming the
snapshot would make the presence check pass vacuously. Count stays at 84.

audit-ui.mjs reads the ten pages from dist/ and resolves Astro's
base-absolute hrefs against it.

Before deleting anything, rendered-text-diff was run across all ten
routes plus both Portuguese pages: every one at parity, 0 missing and 0
extra. That comparison is not repeatable once the legacy files are gone.
computed-style-diff on /full-guide/ stays at 32 differences, so the moves
are style-neutral.

Docs updated to match: README, AGENTS.md, GATES.md, the architecture
context, the operations guide's lab instructions, and the three skills
that told you to serve the vanilla site.

Publishing is not part of this commit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/audit-ui.mjs

@@ -1,18 +1,20 @@
 import { readFileSync, readdirSync, statSync } from 'node:fs';
 import { dirname, join } from 'node:path';
 
+const base = '/ai-for-dummies/';
 const read = (path) => readFileSync(new URL(`../${path}`, import.meta.url), 'utf8');
+// The legacy hand-written pages are gone; the built output is the site now.
 const pages = [
-  'index.html',
-  'full-guide/index.html',
-  'summary/index.html',
-  'models/index.html',
-  'agents/index.html',
-  'skills/index.html',
-  'rules/index.html',
-  'skills-review/index.html',
-  'hands-on/starter/index.html',
-  'hands-on/rules/index.html',
+  'dist/index.html',
+  'dist/full-guide/index.html',
+  'dist/summary/index.html',
+  'dist/models/index.html',
+  'dist/agents/index.html',
+  'dist/skills/index.html',
+  'dist/rules/index.html',
+  'dist/skills-review/index.html',
+  'dist/hands-on/starter/index.html',
+  'dist/hands-on/rules/index.html',
 ];
 const walk = (path) =>
   readdirSync(path).flatMap((name) => {
@@ -49,8 +51,13 @@ for (const [kind, values] of Object.entries(baselineValues)) {
   const missing = values.filter((value) => !builtValues[kind].has(value));
   if (missing.length) throw new Error(`built CSS lost ${kind}: ${missing.join(', ')}`);
 }
-// Legacy fixtures still ship directly. Resolve every var() from the stylesheets
-// that page actually links; Astro's tokens cannot mask a broken standalone page.
+// The hands-on labs still ship their own stylesheet rather than going through
+// Astro. Resolve every var() from the stylesheets each page actually links, so
+// Astro's tokens cannot mask a broken standalone page.
+// Astro emits base-absolute hrefs (`/ai-for-dummies/_astro/x.css`); those are
+// rooted at `dist/`, not at the page's own directory.
+const resolveHref = (page, href) =>
+  href.startsWith(base) ? join('dist', href.slice(base.length)) : join(dirname(page), href);
 for (const page of pages) {
   const html = read(page);
   const linked = [...html.matchAll(/<link[^>]+rel="stylesheet"[^>]+href="([^"]+)"/gi)].map(
@@ -58,7 +65,7 @@ for (const page of pages) {
   );
   const styles = linked
     .filter((href) => !/^https?:/i.test(href))
-    .map((href) => read(join(dirname(page), href)));
+    .map((href) => read(resolveHref(page, href)));
   const defined = new Set(styles.flatMap((css) => [...definitions(css)]));
   const unresolved = new Set(
     styles.flatMap((css) =>