Phase 2: Mode A static site — build, serve, search, stage panel

One Go binary serves a pre-rendered site. No Node, no bundler, no node_modules:
htmx and the SSE extension are vendored files, Markdown and code highlighting
run at build time (goldmark + chroma), and the server only writes files.

Implements docs/phase-2-static-site.md:

  2.1 service skeleton   cmd/build (content -> dist), cmd/server (dist -> HTTP),
                         env-configured, 127.0.0.1:8096, /healthz with separate
                         static / ai / search readiness, --health-check probe,
                         deploy/compose.yml + deploy/Dockerfile at 120m
  2.2 rendering          templ components (Layout, Nav, PillarCard, Stage,
                         EvidenceTable, CodeBlock, Timeline, Footer);
                         `make generate` is a build step and is byte-stable
  2.3 navigation         six-area rail, <details> disclosure under 900px,
                         breadcrumbs, aria-current, L1/L2/L3 with artefact pages
  2.4 stage panel        internal/stage owns the contract; RouteDriver (fragment
                         swap) and SSEDriver (event stream) differ only in the
                         Binding, never in layout. fragment ids live in the
                         contract so route files, links and streamed frames agree
  2.5 search             SQLite FTS5 over titles and body, rebuilt by the build;
                         one handler returns a page without HTMX, a fragment with
                         it. Visitors' FTS operators are never honoured
  2.6 quality floor      print stylesheet, JS-off navigation, focus states,
                         semantic landmarks, dark default; security headers

Definition of Done evidence (see issue AUD-142):
  A1  all pages 200 in a network namespace with no external route
  one binary serves the site; make dist writes 45 pages, 86 fragments, 40 docs
  templ generate is deterministic (md5 identical across runs)
  6 L1 + 6 L2 pages, artefact pages reachable in <= 3 clicks
  FTS5 returns sensible hits for zigbee / signage / routing (tested)
  Lighthouse 100 performance and 100 accessibility, mobile and desktop
  first byte well inside 100ms over loopback (test)
  panel renders from a route driver and re-points at the stream untouched
  print legible: /edge/ renders to a 3-page PDF with the print stylesheet

Also fixes found while finishing the build:
  - reject "." / ".." path segments before ServeMux redirects them into a file
    outside the asset directory (/static/../build.json now 404, was 307->200)
  - make test is the real gate: go test ./... plus the validator self-test

README.md

@@ -37,6 +37,27 @@ This folder **is** the git working copy of `sam/ai-resume`. One repo, one produc
 
 Previously held an abandoned Vite/React scaffold. It was replaced by this build spec; the history is retained because it honestly records the false start, and it is referenced in the site's "alternatives considered" content.
 
+## Build and run
+
+The site is one Go binary serving pre-rendered HTML. There is no Node, no bundler and no
+`node_modules`; `go.sum` is the only dependency lock.
+
+```sh
+nix develop           # go, templ, sqlite3, make, curl
+make validate         # content gate: front-matter against the frozen schema
+make test             # go test ./... plus the validator self-test
+make dist             # templ generate → bin/ → pre-rendered dist/
+make dev              # build, then serve on http://127.0.0.1:8096
+```
+
+`bin/resume-build` reads `content/` and writes `dist/` (pages, stage fragments, the fragment
+manifest, the SQLite FTS5 index, assets). `bin/resume-server` serves `dist/` and never reads
+`content/`, never calls a model, and never opens a socket to another service — that is what
+keeps acceptance test A1 true.
+
+The two things that are not files are `/search` (FTS5 over page titles and body text) and
+`/api/stage/stream` (the presentation panel driven by an event stream instead of a route).
+
 ## Ground rules
 
 - **Do not touch other systems.** No stopping containers, no editing other projects, no `nixos-rebuild`, no Caddy changes except the single block specified in Phase 3 — and that one Sam applies.
@@ -48,8 +69,8 @@ Previously held an abandoned Vite/React scaffold. It was replaced by this build
 ## Current state
 
 - [x] Repo prepared, scaffold retired, build spec written
-- [ ] Phase 1 — content source of truth
-- [ ] Phase 2 — static site
+- [x] Phase 1 — content source of truth (40 documents across six areas, `make validate`)
+- [x] Phase 2 — static site (`make dist`, 45 pages, 86 stage fragments, FTS5 search)
 - [ ] Phase 3 — public deployment
 - [ ] Phase 4 — corpus
 - [ ] Phase 5 — AI overlay