diff --git a/website/API_V2_PLAN.md b/website/API_V2_PLAN.md
index 0a1b4a3..03557a3 100644
--- a/website/API_V2_PLAN.md
+++ b/website/API_V2_PLAN.md
@@ -181,22 +181,64 @@ form-action 'self';
 frame-ancestors 'none';
 ```
 
-Delta vs. the policy in `server/src/app.js` today — the whole change is two directives:
+Delta vs. the policy in `server/src/app.js` today. This was written as two directives; on
+implementation it turned out to be **one**:
 
-- **Add `form-action 'self'`** (currently absent) — blocks an injected `<form action="https://evil">`
-  from POSTing credentials off-origin, an exfil path `connect-src` doesn't cover.
-- **Tighten `frame-ancestors`** `'self'` → `'none'` — nothing legitimately frames the site.
+- ~~**Add `form-action 'self'`** (currently absent)~~ — **it was not absent.** The directives object in
+  `app.js` does not list it, but the middleware is configured `useDefaults: true`, and helmet's default
+  set already supplies `form-action 'self'` — so the header served in production has carried it all
+  along. Verified by capturing the live `Content-Security-Policy` header from the running app rather
+  than reading the config, which is how the plan got this wrong. **No behavioural change here.** It is
+  now written out explicitly in `config/csp.js` anyway: a security directive should not depend on a
+  third-party library's defaults surviving its next major version.
+- **Tighten `frame-ancestors`** `'self'` → `'none'` — nothing legitimately frames the site. **This is
+  the entire behavioural delta of the phase.**
 - Unchanged: `default-src`, `script-src`, `connect-src`, `object-src 'none'`, `base-uri 'self'`, and
   `img-src … https:` (external `BRAND_*` logo/hero and `<img>` in sanitized wiki/news bodies rely on
   `https:`).
 
+The soak is still worth running for that one directive, and arguably it is the directive that most
+needs one: a `frame-ancestors` report is generated by the browser of *whoever framed the site*, so it
+is the only way to discover that something legitimately embeds us before the enforcing policy breaks
+it. Nothing else can tell us that.
+
 **Rollout:** ship via `Content-Security-Policy-Report-Only` with `report-to` for one release, watch for
 violations, then flip to enforce.
 
 Before trusting `script-src 'self'`: Vite's build injects an inline modulepreload-polyfill `<script>`
-into `dist/index.html`, which that directive blocks (harmless, but throws a violation). Confirm it's
-disabled or set `build.modulepreload.polyfill = false` in the Vite config. (The `renderIndexHtml`
-branding injection adds only `<meta>`/`<link>` tags — no inline script, no nonce needed.)
+into `dist/index.html`, which that directive blocks (harmless, but throws a violation).
+**Already handled** — `client/vite.config.js` sets `modulePreload: { polyfill: false }`, so the build
+emits no inline bootstrap script. (The `renderIndexHtml` branding injection adds only `<meta>`/`<link>`
+tags — no inline script, no nonce needed.)
+
+### Where reports go
+
+`report-to` needs somewhere to point, so the report-only PR stands up a same-origin sink:
+**`POST /api/csp-report`** (`server/src/router/cspReport.controller.js`, wired in `app.js`). Same-origin
+on purpose — violation reports describe attacks against this site and are not handed to a third-party
+collector. It writes to the `csp` log tag and stores nothing.
+
+It is mounted outside `/api/v1`, alongside `/api/health`: the browser learns the path from the policy
+header, never from a client build, so it is not part of the versioned client contract. This is the
+`+1` in the route manifest that made PR 0 go first (see § Sequencing).
+
+Necessary properties, since it is an unauthenticated public `POST` (browsers send reports with no
+session, and gating it would silence exactly the anonymous visitors worth hearing about):
+
+- **Both wire formats.** `report-uri` (Firefox, Safari) sends `application/csp-report` with a single
+  hyphenated-key object; `report-to` (Chrome) sends `application/reports+json` with an array of
+  camelCase envelopes. Handling one silently drops half the browsers. Both directives are emitted, and
+  `report-to` additionally needs a `Reporting-Endpoints` response header or it is inert.
+- **Always 204, even for junk.** A 4xx would make the global error handler write an ERROR line quoting
+  the attacker-supplied body — turning an open endpoint into a log-flood primitive. A browser cannot
+  act on an error from a report sink anyway.
+- **Bounded everywhere:** 16 KB body cap, a per-IP rate limit, a fixed field allowlist, and every
+  logged field truncated (`script-sample` is attacker-influenced and can carry a whole inline script).
+
+**Retiring it:** the sink exists for the soak. When the tightened policy flips to enforced and the
+report-only twin is deleted, this endpoint goes with it — *unless* a `report-to` group is deliberately
+kept on the enforced policy, which is a reasonable thing to want. Decide that in the enforce PR rather
+than leaving an orphan route behind.
 
 Tracked follow-ups (own PRs):
 
@@ -302,9 +344,11 @@ proves it, with no router file moved.
   is stable). The manifest keeps only `/api/**`, `/.well-known/**`, and the internal app's routes, so
   it does not change depending on whether CI built the client. Static mounts are not API contract.
 - **The baseline already exists:** [`api-route-inventory.json`](./api-route-inventory.json) in this
-  directory is today's frozen surface — **199 API routes** (110 of them `/api/v1/admin`) plus 2
-  internal. PR 0's generator must **reproduce this file byte-for-byte**; that is PR 0's own acceptance
-  test, and it means the freeze is already in effect before the first router moves.
+  directory is the frozen surface — **199 API routes** (110 of them `/api/v1/admin`) plus 2
+  internal at the time PR 0 was written. PR 0's generator must **reproduce this file byte-for-byte**;
+  that is PR 0's own acceptance test, and it means the freeze is already in effect before the first
+  router moves. *(It did, on first run. The file has since moved to **200** — the CSP report-only PR
+  added `POST /api/csp-report`, the first deliberate, reviewed manifest diff.)*
 - **Runtime introspection, not source parsing.** It is authoritative about mounts, and the route paths
   in `admin.routes.js` sit on the line *after* `adminRouter.get(`, which defeats naive greps.
 - **Not `swagger-output.json`.** That is annotation-derived (only annotated routes appear) and churns
@@ -341,8 +385,11 @@ deliberate `+1` in the manifest — which is exactly the mechanism working as de
 
 1. **PR 0 — route manifest.** Generator + CI check + committed baseline of today's surface. No routers moved. ✅ landed
 2. **PR — CSP report-only.** Tightened policy behind `Content-Security-Policy-Report-Only` + `report-to`,
-   plus the report collector (manifest `+1`).
-3. **PR — CSP enforce.** One release later, assuming a clean violation report.
+   plus the report collector (manifest `+1` — the first deliberate, reviewed manifest diff). ✅ landed
+3. **PR — CSP enforce.** One release later, assuming a clean violation report. **Blocked on real soak
+   data**, not on code: watch the `csp` log tag for `frame-ancestors` reports across one release before
+   flipping. Also decide there whether `/api/csp-report` is retired with the report-only twin or kept
+   as a `report-to` group on the enforced policy.
 4. **PR 1 — admin:** `users`, `account`, `invites`, `auth` (providers).
 5. **PR 2 — admin:** `moderation`, `bot-activity`, `activity`.
 6. **PR 3 — admin (content):** `posts`, `pages`, `wiki`, `uploads`.
diff --git a/website/BACKEND_DESIGN.md b/website/BACKEND_DESIGN.md
index 84ce089..7e732d5 100644
--- a/website/BACKEND_DESIGN.md
+++ b/website/BACKEND_DESIGN.md
@@ -270,7 +270,7 @@ are authoritative, and they answer different questions:
 
 | Artifact | Source of truth for | Generated by |
 |---|---|---|
-| `server/routes.manifest.json` — mirrored as [api-route-inventory.json](./api-route-inventory.json) | **What URLs exist.** 199 public routes + 2 on the internal listener, sorted, method + path only. | `npm run routes:manifest`, by walking the live Express stack |
+| `server/routes.manifest.json` — mirrored as [api-route-inventory.json](./api-route-inventory.json) | **What URLs exist.** 200 public routes + 2 on the internal listener, sorted, method + path only. | `npm run routes:manifest`, by walking the live Express stack |
 | `server/swagger/swagger-output.json` — served at `/api/docs` | **What each route means.** Parameters, bodies, response codes, security. | `npm run swagger`, from `#swagger.*` annotations |
 
 The split is deliberate: Swagger is annotation-derived, so an unannotated route is invisible in it and
@@ -490,7 +490,8 @@ who"; `activity_log` provides the history feed.
 - **bcrypt** hashing (cost 10+); plaintext passwords never stored, logged, or returned.
 - **Rate limiting** (`express-rate-limit`) on `/auth/login` and `/public/contact`.
 - **Validation** (`express-validator`) on all writes; centralized error handler.
-- **helmet** with a Content-Security-Policy tuned for the built React SPA (see `server/src/app.js`):
+- **helmet** with a Content-Security-Policy tuned for the built React SPA. The policies now live in
+  **`server/src/config/csp.js`** (`app.js` only wires them up):
   `default-src 'self'`; `script-src 'self'` (the Vite build emits only external module chunks — the
   inline module-preload polyfill is disabled in `client/vite.config.js` to keep this valid);
   `style-src 'self' 'unsafe-inline' https://fonts.googleapis.com` (React's pervasive inline
@@ -498,11 +499,33 @@ who"; `activity_log` provides the history feed.
   https://fonts.gstatic.com` (Cinzel); `img-src 'self' data: https:` (same-origin uploads, plus
   external https images embedded in wiki/news bodies or `BRAND_*` logo/hero/favicon); `connect-src
   'self'` (REST + SSE are same-origin); `frame-ancestors 'self'`; `object-src 'none'`; `base-uri
-  'self'`. `upgrade-insecure-requests` is intentionally **not** set (TLS terminates at the proxy, there
+  'self'`; `form-action 'self'` (blocks an injected `<form action="https://evil">` from POSTing
+  credentials off-origin — an exfil path `connect-src` does not cover; it was always emitted via
+  helmet's `useDefaults` and is now pinned explicitly so it cannot vanish under a helmet upgrade).
+  `upgrade-insecure-requests` is intentionally **not** set (TLS terminates at the proxy, there
   are no mixed-content subresources, and it would break a local `npm start` over plain http). The
   `/api/docs` Swagger UI route gets a **looser** policy that additionally allows inline script/style,
   since swagger-ui-express injects an inline bootstrap. helmet also strips `X-Powered-By`; the two
   internal-only listeners (`internalApp.js`, `bot/src/app.js`) disable it explicitly too.
+- **A second, tightened policy ships alongside on `Content-Security-Policy-Report-Only`** for one
+  release before it replaces the enforced one (`docs/website/API_V2_PLAN.md` § Phase 1). It is derived
+  from the enforced policy so the two cannot drift, and differs by exactly one directive:
+  `frame-ancestors 'self'` → **`'none'`**. Serving both headers at once means the live policy keeps
+  protecting users while anything the tightened version would break arrives as a report rather than as
+  a broken page — and for `frame-ancestors` specifically, a report from the browser of whoever framed
+  the site is the only way to learn that something does.
+- **`POST /api/csp-report`** is the same-origin violation sink that `report-to` / `report-uri` point at
+  (`report-to` additionally requires the `Reporting-Endpoints` response header, which is set alongside).
+  Same-origin on purpose: reports describe attacks against this site and are not handed to a
+  third-party collector. It parses **both** wire formats (`application/csp-report` from Firefox/Safari,
+  `application/reports+json` from Chrome's Reporting API — handling one drops half the browsers),
+  writes to the `csp` log tag and **stores nothing**. Necessarily unauthenticated (browsers send
+  reports with no session), so it is bounded on every axis: 16 KB body cap, per-IP rate limit, fixed
+  field allowlist, every logged field truncated, and **always 204 — even for malformed input**, since a
+  4xx would make the global error handler log the attacker-supplied body and turn an open endpoint into
+  a log-flood primitive. Mounted outside `/api/v1` next to `/api/health`: the browser learns the path
+  from the policy header, never from a client build, so it is not part of the versioned client
+  contract.
 - **Admin not indexed**: `X-Robots-Tag: noindex, nofollow` on `/api/v1/admin` and the admin SPA routes; `robots.txt` disallows `/admin`.
 - **No directory browsing** (express.static doesn't list; no `serve-index`).
 - **No hardcoded credentials**: first admin via `seed.js` reading `ADMIN_USERNAME`/`ADMIN_PASSWORD` from env (created only if no users exist); `.env` git-ignored, `.env.example` committed.
@@ -527,7 +550,11 @@ instead. Errors never leak credentials.
 
 `utils/logger.js` — a small dependency-free logger with **two transports, console + file**,
 and four levels (`error`/`warn`/`info`/`debug`). Each line is timestamped and tagged by
-subsystem (`[server]`, `[http]`, `[db]`, `[auth]`, `[admin]`, `[ratelimit]`, …).
+subsystem (`[server]`, `[http]`, `[db]`, `[auth]`, `[admin]`, `[ratelimit]`, `[csp]`, …).
+
+> During the CSP report-only soak, `[csp]` is the tag to watch: a `csp violation` warn line with
+> `directive: frame-ancestors` means something really does frame the site and the enforce PR would
+> break it. Silence across one release is the green light to flip.
 
 - **Console**: color on a TTY, plain in Docker; verbosity = `LOG_LEVEL` (default `info`).
 - **File**: plain text appended to `LOG_DIR/LOG_FILE` (default `<server>/logs/app.log`,
diff --git a/website/api-route-inventory.json b/website/api-route-inventory.json
index 7c0db62..63a0207 100644
--- a/website/api-route-inventory.json
+++ b/website/api-route-inventory.json
@@ -5,6 +5,10 @@
       "method": "GET",
       "path": "/.well-known/assetlinks.json"
     },
+    {
+      "method": "POST",
+      "path": "/api/csp-report"
+    },
     {
       "method": "GET",
       "path": "/api/docs.json"