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>

legacy/styles/change-lens.css

@@ -0,0 +1,4 @@
+.change-lens{border:1px solid var(--ink);background:#123042;color:var(--paper);animation:lens-enter .28s ease both}.change-lens>header{display:flex;justify-content:space-between;gap:20px;align-items:start;padding:22px 24px;border-bottom:1px solid #466274}.change-lens span{color:var(--gold);font:700 10px var(--font-mono);letter-spacing:.1em}.change-lens h3{margin:7px 0 0;font-size:clamp(24px,3vw,40px);line-height:1.02;letter-spacing:-.05em}.change-lens>header button{padding:9px 11px;border:1px solid #557080;color:var(--paper);background:transparent;cursor:pointer;font:700 10px var(--font-mono)}.change-lens>header button:hover{color:var(--ink);background:var(--gold)}.change-lens>p{max-width:67ch;margin:0;padding:19px 24px;color:#c6d2d7}.change-rows{display:grid;gap:1px;background:#466274}.change-rows article{display:grid;grid-template-columns:120px minmax(0,1fr) minmax(0,1fr) minmax(220px,.85fr);gap:1px;background:#466274}.change-rows article>*{min-width:0;margin:0;padding:17px;background:#173b4f}.change-rows article>span{color:var(--gold);font:700 10px/1.4 var(--font-mono)}.change-rows b{font:700 10px var(--font-mono);letter-spacing:.07em;text-transform:uppercase}.change-rows div:first-of-type b{color:#e89a8e}.change-rows div:nth-of-type(2) b{color:#9bcba7}.change-rows aside{background:#1d455b}.change-rows aside b{color:var(--gold)}.change-rows p{margin:7px 0 0;color:#d4dfe3;font-size:12px;line-height:1.55}.preview header [data-lens]{color:var(--gold);border-color:var(--gold)}@keyframes lens-enter{from{opacity:.15;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@media(max-width:1000px){.change-rows article{grid-template-columns:100px 1fr 1fr}.change-rows aside{grid-column:2/-1}}@media(max-width:620px){.change-lens>header{display:block}.change-lens>header button{margin-top:14px}.change-rows article{grid-template-columns:1fr}.change-rows article>span{padding-bottom:6px}.change-rows aside{grid-column:auto}.change-lens>p{padding:17px}.change-lens>header{padding:18px}.change-rows p{font-size:13px}}@media(prefers-reduced-motion:reduce){.change-lens{animation:none}}
+
+/* A compact, scrollable comparison keeps long skill revisions reviewable. */
+.skill-diff{border:1px solid var(--ink);background:#102b3a;color:var(--paper);animation:lens-enter .28s ease both}.skill-diff>header{display:flex;justify-content:space-between;gap:20px;align-items:start;padding:22px 24px;border-bottom:1px solid #466274}.skill-diff span{color:var(--gold);font:700 10px var(--font-mono);letter-spacing:.1em}.skill-diff h3{margin:7px 0 0;font-size:clamp(24px,3vw,40px);line-height:1.02;letter-spacing:-.05em}.skill-diff>header button{padding:9px 11px;border:1px solid #557080;color:var(--paper);background:transparent;cursor:pointer;font:700 10px var(--font-mono)}.skill-diff>header button:hover{color:var(--ink);background:var(--gold)}.skill-diff>p{margin:0;padding:17px 24px;color:#c6d2d7}.diff-lines{max-height:540px;overflow:auto;border-top:1px solid #466274;font:12px/1.55 var(--font-mono)}.diff-lines p{display:grid;grid-template-columns:42px minmax(0,1fr);gap:11px;margin:0;padding:4px 16px;white-space:pre-wrap;overflow-wrap:anywhere}.diff-lines span{color:#91aab7}.diff-lines .added{color:#d5f1d6;background:#1a4b42}.diff-lines .added span{color:#a9e3ae}.diff-lines .removed{color:#ffd7d0;background:#572f32}.diff-lines .removed span{color:#ffb5a8}.preview header [data-diff]{color:#c6d2d7;border-color:#557080}@media(max-width:620px){.skill-diff>header{display:block}.skill-diff>header button{margin-top:14px}.diff-lines p{grid-template-columns:30px minmax(0,1fr);padding:4px 12px}}@media(prefers-reduced-motion:reduce){.skill-diff{animation:none}}