security: fix full audit findings (v0.32.0)

Full list of the audit's confirmed findings and their fixes:

- Stored XSS via unescaped JSON-LD on the public recipe page
  (app/r/[id]/page.tsx) — escape < before injecting.
- CSP allowed unsafe-eval in production — now dev-only (Next prod
  never eval()s; only its HMR does).
- avatarUrl accepted any URL with no ownership check — now takes an
  avatarKey issued by avatar-presign, validated server-side, same
  pattern as recipe/review photos.
- No session revocation on password change/reset — both now revoke
  other sessions (revokeOtherSessions: true, revokeSessionsOnPasswordReset).
- Rate-limit bypass via spoofable X-Forwarded-For — take the last
  (proxy-appended) hop instead of the first (client-supplied) one,
  matching the single-Traefik-hop topology.
- Webhook signing secrets stored plaintext — now AES-256-GCM
  encrypted like every other secret in this app, with a legacy-
  plaintext fallback for pre-existing rows (bare hex has no ":", our
  ciphertext format always does).
- Better Auth's own rate limiter defaulted to in-memory storage,
  ineffective across replicas — now backed by the same Redis as
  lib/rate-limit.ts (secondaryStorage), with storeSessionInDatabase
  explicit so session storage itself doesn't move as a side effect.
- Presigned upload URLs didn't bind the declared file size to the
  actual upload, letting a client under-declare size (and quota
  charge) then PUT an arbitrarily large object — switched to S3
  presigned POST with a signed content-length-range condition,
  enforced by the storage server itself.
- generateMetadata() on the recipe page skipped the visibility
  filter the page body uses, leaking a private recipe's title via
  <title> to any signed-in user with the id.
- Block/unblock had no rate limit, unlike follow/unfollow.
- AI quota was charged even when a user's own BYOK key was used
  (their own credentials/billing) — added an isByok flag through
  the config-resolution chain and skip the charge when set. Also
  wired BYOK into generate/generate-from-idea/translate/import-url,
  which never looked it up at all before.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,20 @@
 
 All notable changes to Epicure are documented here. This file is mirrored in-app at `/changelog` (and in the admin dashboard) via `apps/web/lib/changelog.ts` — update both together.
 
+## 0.32.0 — 2026-07-14 17:10
+
+### Security
+- Fixed a stored-XSS hole in public recipe pages' embedded structured data, and tightened the production Content-Security-Policy so script injection like it can't execute even if a similar bug slips in again.
+- Avatar photos now require proof you actually own the upload — previously any URL was accepted, including another user's uploaded photo key.
+- Changing your password now signs out every other active session, and so does resetting a forgotten password.
+- Fixed a rate-limit bypass on public share-link throttling caused by trusting a spoofable header.
+- Webhook signing secrets are now encrypted at rest, matching how API keys and other secrets are already stored.
+- Login/2FA/password-reset rate limiting now shares Redis instead of quietly resetting per server instance.
+- Photo/avatar uploads are now size-capped by the storage server itself, not just a number the client could lie about.
+- A private recipe's title could leak via its page's browser-tab title to any signed-in user who had the link — fixed to respect the same visibility rules as the page itself.
+- Blocking/unblocking a user is now rate-limited, matching follow/unfollow.
+- AI calls made with your own API key (Settings → AI Keys) no longer count against your monthly AI-call limit.
+
 ## 0.31.0 — 2026-07-14 16:35
 
 ### Added