v1.1.0:9 — P2 hardening: input-validation 400s, auth rate-limit, XFF anti-spoof, non-root container

P2 batch from the 2026-06-13 full-eval (EVALUATION.md / ROADMAP.md), reviewed by the reviewer agent. App-code + packaging only; no schema or data change, existing /data untouched.

Input validation: malformed JSON bodies, invalid date, and out-of-range or non-numeric pagination on /api/workouts now return 400 instead of 500. New lib/http.ts readJsonBody maps a bad body to a ZodError across the 11 CRUD routes whose catch maps ZodError to 400; me/import and admin/signups guard request.json() in an explicit try/catch.

Rate limiting: POST /api/auth now shares the UI login server action's per-IP 10-per-15min cap and returns 429 + Retry-After. clientIpFromHeaders reads the rightmost (trusted-proxy-appended) X-Forwarded-For entry instead of the spoofable leftmost.

Container: drops root. The entrypoint prepares /data as root, chowns it to nextjs, then exec su-exec nextjs:nodejs node server.js (su-exec added to the runner image). The container drop needs live sideload verification.

ROADMAP.md

@@ -10,11 +10,10 @@ Longer-term backlog. Near-term state + next steps live in `AGENTS.md` → Curren
 ## Security & hardening (from 2026-06-13 full-eval; full detail + file:line in `EVALUATION.md`)
 
 - **Next.js 14→15 major bump** (CVEs: RSC DoS, WS-upgrade SSRF, App Router XSS). Own tested change — breaking App Router/caching semantics, needs its own build + sideload verification.
-- Input-validation 500s → should be 400: invalid `date`, malformed JSON body, negative pagination `offset` on `/api/workouts` (+ `import/exercises/seed`). One shared `try{json}→400` + Zod guard fixes the set.
-- `POST /api/auth` has no rate limiting (the UI server-action is capped; the raw API isn't) → brute-forceable.
-- Rate limiter trusts the spoofable leftmost `X-Forwarded-For` (`lib/rateLimit.ts`) — verify whether the StartOS proxy overwrites XFF on the live box.
-- Container runs as **root** — add `USER nextjs` to `start9/0.4/Dockerfile`.
-- P3 hardening batch: login timing oracle (dummy bcrypt on unknown email), CSP `unsafe-eval` vs comment, `/api/health` info disclosure, rate-limit map leak, `exerciseId` ownership unchecked on workout PATCH/sets POST, 30-day sessions, no text max-length.
+- **Still open — verify on the box:** whether the StartOS proxy forwards real client IPs to the app. The rate limiter now keys on the rightmost (trusted-proxy) `X-Forwarded-For` entry; if the proxy instead makes every client look like one IP, the per-IP cap collapses to a single global bucket. Confirm with live headers.
+- P3 hardening batch: login timing oracle (dummy bcrypt on unknown email), CSP `unsafe-eval` vs comment, `/api/health` info disclosure, rate-limit map leak, `exerciseId` ownership unchecked on workout PATCH/sets POST, 30-day sessions, no text max-length. Also unify the 3rd JSON-parse pattern in `programs/[id]/days/[dayId]/start` (`try{json}catch{→{}}`).
+
+Done in 1.1.0:9 (P2 batch): input-validation 500s → 400 (`lib/http.ts readJsonBody` + explicit guards); `POST /api/auth` rate-limited; XFF anti-spoof; container drops root via su-exec.
 
 ## Packaging / distribution