feat(sp23): live-verification fixes from end-to-end bring-up

After the 8-commit SP23 implementation landed, kicking the tires on
`docker compose build && docker compose up -d` (the gated DOCKER_TESTS=1
live test) surfaced five real bugs that don't show up in unit tests:

1. Backend wheel was built from the stub `__init__.py`, not the real
   source. The Dockerfile's 'stub __init__, wheel, copy src, wheel
   again' pattern silently kept the first wheel's contents — only
   `__init__.py` got re-stubbed. The installed package had an empty
   `__init__.py`, so `from cyclone import __version__` failed at import
   time and the backend kept crashing in a restart loop.
   Fix: single `COPY src/` + single `pip wheel`. Comment explains
   why the stub trick is gone for good.

2. Backend binds to 127.0.0.1 (intentional — local-only by design,
   see CLAUDE.md). But that means the frontend container can't reach
   it over the compose bridge network — nginx got 'Connection refused'.
   Fix: `CYCLONE_HOST` env var, defaults to 127.0.0.1 (preserves local
   posture for non-Docker runs), set to 0.0.0.0 by the docker-compose
   backend service. Network isolation is provided by the compose bridge
   network (only `cyclone-frontend` joins).

3. Healthcheck probed `/api/healthz` (404 — the route is `/api/health`).
   Same in: backend Dockerfile HEALTHCHECK, docker-compose healthcheck,
   nginx.conf doesn't have one (frontend proxies through), RUNBOOK.md,
   scripts/post-deploy.sh, scripts/smoke.sh.
   Fix: `/api/healthz` → `/api/health` everywhere SP23 owns.

4. The auth matrix in `cyclone.auth.permissions` had
   `("GET", "/api/healthz"): set()` — which is the WRONG path (the
   route is `/api/health`). So even after fixing the healthcheck URL,
   the public auth bypass wouldn't have applied to `/api/health` and
   it would have been DENY-by-default (fail-closed).
   Fix: matrix entry updated to `/api/health`.

5. nginx upstream pointed at `cyclone-backend` (the project+service
   name), but compose v2 only resolves the bare service name (`backend`)
   over the bridge network. nginx crashed at config-load with 'host not
   found in upstream cyclone-backend'.
   Fix: `cyclone-backend:8000` → `backend:8000` in nginx.conf + spec
   + plan.

6. Frontend HEALTHCHECK used `http://localhost:8080/`. nginx in the
   alpine image listens on IPv6 (per the entrypoint's IPv6-by-default
   script), so `localhost` (which prefers IPv6 `::1` in musl) connects,
   but the resolved flow inside wget is unreliable. `127.0.0.1` works.
   Fix: HEALTHCHECK uses `http://127.0.0.1:8080/`.

Also moves `frontend/Dockerfile` → `Dockerfile.frontend` and
`frontend/nginx.conf` → `nginx.conf` at repo root (because the
frontend lives at the repo root, not in `frontend/`, and compose's
`build.context: .` needs them at the same root as compose.yml).
The frontend's pre-existing `.dockerignore` was empty/unused, so it's
dropped — the root `.dockerignore` covers it.

Adds `docker-compose.override.yml` for local bring-up testing on a
host without sudo. Production uses `/etc/cyclone/secrets/` directly.

Verified end-to-end on this dev host with `DOCKER_TESTS=1`:
- Both containers `(healthy)` within ~60s
- `curl http://localhost:8080/api/health` → 200 with valid JSON
- Login as admin → 200, /api/auth/me → 200
- `POST /api/parse-837` with docs/goodclaim.x12 → 200, batch created
- Full backend test suite: 1014 passed, 9 skipped (prodfiles gitignored)

scripts/post-deploy.sh

@@ -4,7 +4,7 @@
 set -euo pipefail
 
 LOG_DIR="/var/log/cyclone"
-HEALTHCHECK_URL="${CYCLONE_HEALTHCHECK_URL:-http://localhost:8080/api/healthz}"
+HEALTHCHECK_URL="${CYCLONE_HEALTHCHECK_URL:-http://localhost:8080/api/health}"
 HEALTHCHECK_EMAIL="${CYCLONE_HEALTHCHECK_EMAIL:-root}"
 CRON_USER="${CYCLONE_CRON_USER:-root}"
 
@@ -32,11 +32,11 @@ mkdir -p "${LOG_DIR}"
 chmod 755 "${LOG_DIR}"
 
 # 2. Healthcheck cron — every 5 minutes, email if down.
-CRON_LINE="*/5 * * * * curl -fsS --max-time 10 ${HEALTHCHECK_URL} >/dev/null 2>&1 || echo 'Cyclone DOWN at \$(date)' | mail -s 'Cyclone healthz FAIL' ${HEALTHCHECK_EMAIL}"
+CRON_LINE="*/5 * * * * curl -fsS --max-time 10 ${HEALTHCHECK_URL} >/dev/null 2>&1 || echo 'Cyclone DOWN at \$(date)' | mail -s 'Cyclone health FAIL' ${HEALTHCHECK_EMAIL}"
 TMP_CRON="$(mktemp)"
 crontab -u "${CRON_USER}" -l 2>/dev/null > "${TMP_CRON}" || true
 # Remove any existing cyclone healthcheck line, then re-add.
-grep -v -F "Cyclone healthz" "${TMP_CRON}" > "${TMP_CRON}.new" || cp "${TMP_CRON}" "${TMP_CRON}.new"
+grep -v -F "Cyclone health" "${TMP_CRON}" > "${TMP_CRON}.new" || cp "${TMP_CRON}" "${TMP_CRON}.new"
 echo "${CRON_LINE}" >> "${TMP_CRON}.new"
 crontab -u "${CRON_USER}" "${TMP_CRON}.new"
 rm -f "${TMP_CRON}" "${TMP_CRON}.new"

scripts/smoke.sh

@@ -19,11 +19,11 @@ SAMPLE_837="${CYCLONE_SMOKE_SAMPLE:-docs/prodfiles/co_medicaid/sample_837p.txt}"
 cleanup() { rm -f "${COOKIE_JAR}" /tmp/cyclone_smoke_export.zip; }
 trap cleanup EXIT
 
-echo "==> waiting for healthz..."
+echo "==> waiting for health..."
 for i in {1..30}; do
-    if curl -fsS "${BASE_URL}/api/healthz" >/dev/null 2>&1; then break; fi
+    if curl -fsS "${BASE_URL}/api/health" >/dev/null 2>&1; then break; fi
     sleep 2
-    [[ $i -eq 30 ]] && { echo "FAIL: healthz never came up"; exit 1; }
+    [[ $i -eq 30 ]] && { echo "FAIL: health never came up"; exit 1; }
 done
 echo "    ok"