Adds the demonstrator's public-facing welcome page and turns the comms
plan's stage-gate progress cadence into a per-spec "plans -> achievements"
discipline, recorded register-first as a flagged candidate.

docs/assay-home.html — hand-authored Home/Overview (comms plan §4 page 1;
projects concept §1). Self-contained and static (comms plan §6.4): inline
CSS/SVG, no external assets, theme-aware (light/dark). Reuses the
demonstrator's own band-pill / four-stop verdict colour language (ui-design
§2, comms plan §8) so the site looks like the honesty it reports. Sections:
objectives + premise, the spine diagram (Knowledge -> Compile -> Score ->
Analyse -> Surfaces, status-coloured), links to the published surfaces
(gallery/, wireframes.html), theses A-H with honest state chips, a
progress/achievements tracker (Stage 0/1 done, Stage 2 in progress), a
clearly-labelled forthcoming-articles section (no dead link), the
banded-honesty stance, and the canonical-doc index. Honesty guardrails hold:
nothing shown as done the repository does not contain; the fictional Meridian
framing is stated on every relevant block.

Deployment note: the publish pipeline (PR #17, scripts/build-site.ts) copies
this file to the site root as index.html; its relative app links resolve once
deployed. Left unwired here to avoid conflicting with that in-flight work.

Process change (register-first, ASSAY-DEC-2):
- concept §6.12 — flagged candidate: each build spec carries a home-page-
  currency step in its definition of "done" when it moves a thesis/stage from
  planned to demonstrated. Not yet ratified.
- comms plan §9 + .specify/templates/tasks-template.md — the step wired in
  provisionally, marked pending ratification (the DEC-16 / sparse-channel
  "build against the flagged candidate" pattern).

npm test: 89 passing; typecheck clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011vg1J8cqoCaAdUD1qMMnWS

PR #17's publish pipeline is on main, so the deferred wiring is unblocked.
build-site.ts now copies the hand-authored Home page (docs/assay-home.html)
to site/index.html instead of generating a minimal inline landing, so the
demonstrator's front door is the reviewed, on-brand page rather than a stub.

Honest preview labelling is preserved: a <!--BUILD_BADGE--> placeholder in the
Home page is replaced with a "preview of PR #N · <sha>" badge only when
PR_NUMBER is set. Production (main) and local builds ship badge-free — a
preview must announce itself; the real site needs no label.

Verified: npm run build:site writes the Home page as root (gallery/ and
wireframes.html alongside); preview build injects the badge + commit link;
production build is clean. typecheck clean; committed gallery output
byte-identical (regeneration is a no-op).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011vg1J8cqoCaAdUD1qMMnWS