docs(website): record the PR 3 admin router split (posts, uploads, wiki, pages)

Adds a "PR 3 — as landed" section to API_V2_PLAN.md and ticks the sequencing
list. 31 routes extracted, 33 left in admin.routes.js; all four zero-diff gates
came back clean and 434 server tests passed.

Findings carried forward:

- The residual 33 is exactly PR 4's list, so admin.routes.js is deleted by
  PR 4 rather than PR 5.
- First shared module in the split: the multer config, because POST
  /posts/upload and POST /uploads no longer live in the same file.
- POST /uploads keeps its Admin · Posts swagger tag — retagging is a real
  OpenAPI diff and does not belong in a route-move PR.
- The wiki router has load-bearing intra-file route order (/categories and
  /tags ahead of /:slug) that no gate can catch, because the manifest sorts
  its entries. Verified by introspecting the built router stack instead.

BACKEND_DESIGN.md §2 gets the four new routers plus imageUpload.js in the
folder tree, and §4 notes that the content capabilities add no gate beyond
staffOnly.

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

website/API_V2_PLAN.md

@@ -376,6 +376,51 @@ Notes:
 - **`modAccess` stays in the residual file** — the `/shard/*` in-game staff operations still use it
   and do not move until PR 4. Its comment there was retargeted rather than deleted.
 
+### PR 3 — as landed
+
+`posts`, `uploads`, `wiki` and `pages` — 31 routes, leaving 33 in the residual file. The content tier,
+and the first split PR where no gate moved at all: all four capabilities are editor-tier, so the shared
+`staffOnly` in `admin/index.js` is their whole gate.
+
+| Router | Routes | Prefix | Extra gate |
+|---|---|---|---|
+| `posts.router.js` | 9 | `/admin/posts` | none — editor tier |
+| `uploads.router.js` | 1 | `/admin/uploads` | none — editor tier |
+| `wiki.router.js` | 14 | `/admin/wiki` | none — editor tier |
+| `pages.router.js` | 7 | `/admin/pages` | none — editor tier |
+| `admin.routes.js` (residual) | 33 | group root, mounted last | unchanged |
+
+All four gates zero-diff: `routes.manifest.json` (200 public + 2 internal), `routes.guards.json`,
+`swagger-output.json` (198 operations), and `docs/website/api-route-inventory.json` was already in
+sync. 434 server tests green.
+
+Notes:
+
+- **The residual 33 is exactly PR 4's list** — `shard` 16, `email` 6, `uo-link` 5, `settings` 2,
+  `discord-bot` 2, `dashboard` 1, `site-mode` 1. So `admin.routes.js` is deleted by PR 4, one PR
+  earlier than the sequencing list implies, and PR 5 touches only `public/*`, `player/*` and `auth/*`.
+- **A shared module was unavoidable here, and it is the first one in the split.** The multer config
+  (upload dir, mimetype→extension allowlist, 8 MB cap) was defined inline in `admin.routes.js` and used
+  by *two* routes that this PR puts in different files: `POST /posts/upload` (→ `{image_url}`) and
+  `POST /uploads` (→ `{url}`). It moved to `admin/imageUpload.js` rather than being duplicated —
+  duplicating a security allowlist is how the two copies drift. It stays in `admin/` deliberately:
+  `UPLOAD_DIR` is resolved `__dirname`-relative, so relocating the file would silently repoint the
+  upload directory. Guard freshness is unaffected — multer's middleware is named `multerMiddleware`
+  wherever it is constructed, so `routes.guards.json` did not move.
+- **`POST /uploads` keeps its `Admin · Posts` swagger tag**, which now disagrees with its filename. The
+  acceptance criterion is a byte-identical spec, so retagging is a real OpenAPI diff and does not
+  belong in a route-move PR. Same call as PR 1's `/shard/*` tag mismatch: fix tags in a PR that is
+  *about* tags.
+- **The wiki router is the first one with load-bearing intra-file route order.** `/categories` and
+  `/tags` are literal paths that must stay ahead of `/:slug`, or `GET /admin/wiki/categories` gets
+  dispatched as a page whose slug is "categories". **The manifest cannot catch this — it sorts its
+  entries, so a reordering is invisible in all three gates.** It was verified separately by
+  introspecting the built router stack and asserting the last literal layer precedes the first `/:slug`
+  layer. Any future PR moving `/:slug`-style routes needs the same explicit check.
+- **`/admin/pages` (CMS page builder) and `/admin/shard/pages` (in-game help-page queue) are unrelated
+  capabilities that read alike** — the latter stays with `shard` in PR 4. Same trap as PR 2's
+  `activity` / `dashboard` / `bot-activity` trio.
+
 ### The swagger path-normalization prerequisite (landed before PR 1)
 
 swagger-autogen builds a path by string-concatenating the mount prefix with the route argument, so a
@@ -485,9 +530,10 @@ deliberate `+1` in the manifest — which is exactly the mechanism working as de
    as a `report-to` group on the enforced policy.
 4. **PR 1 — admin:** `users`, `account`, `invites`, `auth` (providers). ✅ landed
 5. **PR 2 — admin:** `moderation`, `bot-activity`, `activity`. ✅ landed
-6. **PR 3 — admin (content):** `posts`, `pages`, `wiki`, `uploads`.
+6. **PR 3 — admin (content):** `posts`, `pages`, `wiki`, `uploads`. ✅ landed
 7. **PR 4 — admin (ops/config):** `shard`, `uo-link`, `email`, `discord-bot`, `settings`, `site-mode`,
-   `dashboard`. (`activity` went with PR 2 — see § PR 2 — as landed.)
+   `dashboard`. (`activity` went with PR 2 — see § PR 2 — as landed.) **This is the whole residual
+   file** — `admin.routes.js` is deleted here, not by PR 5.
 8. **PR 5 — `public/*` + `player/*`** (and the residual `auth/*` grouping).
 
 Each PR: **zero-line diff in `routes.manifest.json`**, server tests green

website/BACKEND_DESIGN.md

@@ -34,10 +34,10 @@ Skeleton from the spec, with a small number of justified additions marked **(+)*
 > every URL unchanged**. This section and §4 get updated as each split PR lands. See
 > [API_V2_PLAN.md](./API_V2_PLAN.md) § Phase 2.
 >
-> **Landed so far:** admin `users`, `account`, `invites`, `auth/providers` (PR 1, 28 routes) and
+> **Landed so far:** admin `users`, `account`, `invites`, `auth/providers` (PR 1, 28 routes),
-> `moderation`, `bot-activity`, `activity` (PR 2, 18 routes) now live in their own routers under
+> `moderation`, `bot-activity`, `activity` (PR 2, 18 routes) and `posts`, `uploads`, `wiki`, `pages`
-> `admin/`, behind a new `admin/index.js`. The remaining 64 admin routes are still in
+> (PR 3, 31 routes) now live in their own routers under `admin/`, behind a new `admin/index.js`. The
-> `admin.routes.js`, and `public/` and `player/` are untouched.
+> remaining 33 admin routes are still in `admin.routes.js`, and `public/` and `player/` are untouched.
 >
 > "Every URL unchanged" is enforced mechanically, not by review: `server/scripts/routeManifest.js`
 > (`npm run routes:manifest`) walks the live Express stack and writes the sorted
@@ -74,7 +74,16 @@ server/
                  botActivity.router.js   (2)  /admin/bot-activity  — adminOnly
                  activity.router.js      (1)  /admin/activity      — staff-wide
                                               audit log, no extra gate
-                 admin.routes.js        (64)  everything not yet split, mounted
+                 posts.router.js         (9)  /admin/posts    — editor tier, no
+                                              gate beyond staffOnly
+                 uploads.router.js       (1)  /admin/uploads  — rich-text editor
+                                              image upload
+                 wiki.router.js         (14)  /admin/wiki     — pages, revisions,
+                                              categories, tags
+                 pages.router.js         (7)  /admin/pages    — CMS page builder
+                 imageUpload.js               shared multer config for the two
+                                              upload routes above (not a router)
+                 admin.routes.js        (33)  everything not yet split, mounted
                                               last at the group root; goes away
                                               when the final split PR lands
                  admin.controller.js + the per-capability controllers
@@ -467,9 +476,11 @@ Public content GETs pass through the **siteMode** gate (§5).
 
 `admin/index.js` applies the shared gate and mounts each capability router at the prefix it owns;
 `users`, `invites`, `auth/providers` and `bot-activity` add `adminOnly` on top, and `moderation` adds
-`modAccess` (admin + moderator, so editors are excluded). Routes not yet extracted still live
+`modAccess` (admin + moderator, so editors are excluded). The content capabilities — `posts`,
-in `admin.routes.js`, mounted last at the group root. The URLs below are unaffected by which file a
+`uploads`, `wiki`, `pages` — add nothing: managing content is the editor tier's job, so `staffOnly` is
-route currently sits in — that is the property the route manifest freezes.
+the whole gate. Routes not yet extracted still live in `admin.routes.js`, mounted last at the group
+root. The URLs below are unaffected by which file a route currently sits in — that is the property the
+route manifest freezes.
 | Method | Path | Purpose |
 |---|---|---|
 | GET | `/dashboard` | current mode, last change time + who, content counts, recent activity |