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/verify.mjs

@@ -46,7 +46,7 @@ const source = {
     read('src/content/providers/claude.json'),
     read('src/content/providers/gemini.json'),
   ].join('\n'),
-  starter: read('hands-on/starter/app.js'),
+  starter: read('public/hands-on/starter/app.js'),
   voteService: read('vote-service/main.go'),
   ndoReview: read('src/content/reviews/ndo-repro.md'),
 };
@@ -73,32 +73,16 @@ if (rendered(html.starter) !== snapshot('hands-on/starter.txt'))
 if (rendered(html.labRules) !== snapshot('hands-on/rules.txt'))
   throw new Error('rules lab rendered-text snapshot changed');
 
-const braceMatch = (source, open) => {
-  let depth = 0;
-  let quote = '';
-  let escaped = false;
-  for (let index = open; index < source.length; index += 1) {
-    const character = source[index];
-    if (quote) {
-      if (escaped) escaped = false;
-      else if (character === '\\') escaped = true;
-      else if (character === quote) quote = '';
-      continue;
-    }
-    if (character === "'" || character === '"' || character === '`') quote = character;
-    else if (character === '{') depth += 1;
-    else if (character === '}' && --depth === 0) return index;
-  }
-  throw new Error('could not brace-match legacy Portuguese translations');
-};
-const legacyGuide = read('app.js');
-const translationsStart = legacyGuide.indexOf('const translations =');
-const objectStart = legacyGuide.indexOf('{', translationsStart);
-const objectEnd = braceMatch(legacyGuide, objectStart);
-const translations = Function(`return (${legacyGuide.slice(objectStart, objectEnd + 1)})`)();
-const portuguese = Object.values(translations.pt).map(rendered);
+// The 102 Portuguese strings were extracted verbatim from the legacy
+// `app.js` `translations.pt` object at cutover, before that file was deleted.
+// This is a legacy capture, not a snapshot of the Astro build: it still asserts
+// against an independent source, which is the whole point of the check.
+const portuguese = JSON.parse(read('.agents/snapshots/full-guide-pt.json')).map(rendered);
 if (portuguese.length !== 102)
-  throw new Error('full-guide Portuguese source no longer has 102 translated strings');
+  throw new Error('full-guide Portuguese snapshot no longer has 102 translated strings');
+// Without this, trimming the snapshot would make the check below pass vacuously.
+if (portuguese.some((value) => !value.trim()))
+  throw new Error('full-guide Portuguese snapshot has an empty entry');
 if (!portuguese.every((value) => rendered(html.guide).includes(value)))
   throw new Error('built full-guide lost a Portuguese translation');