feat(modules): ctx additions and the post-hook registry (API 1.1.0)

Everything the extraction needed from core that ctx did not already offer.
Additions only, so minor.

ctx.activity.log, because an admin action a module performs has to land in
core's one audit log or the trail has a hole exactly where a module operates the
game -- a module keeping its own log would be a second place to look, which in
practice means a place nobody looks. Write-only; reading the log is the admin
panel's job and it spans every actor.

ctx.users.getById, one function for one caller: the admin.users.detail slot
router needs the user its prefix names. ctx.site.baseUrl, because a module has
to build absolute links and §2.7 forbids it reading core's APP_BASE_URL -- a
getter, not a captured string, so it cannot go stale against the env.

ctx.middleware.rateLimit is core's makeLimiter, plus accountChangeLimiter handed
over whole. The split is deliberate: a module states its own window and cap
because it knows what its endpoints cost, and takes the plumbing from core so
there is one express-rate-limit in the process and one place a breach is logged.
accountChangeLimiter is shared policy -- core's /auth/me and /player/account sit
behind the same counter -- so a module's account-change route has to land IN it
rather than beside it. marketLimiter was UO policy living in core's file and
leaves with the route it guards.

registerPostHook is the fourth registry, and the last thing binding core to the
module. Core's post controller called newsGump.syncPost directly: core's CMS
naming a UO file. It now publishes what it already knows and a subscriber
decides what to do with it. Not folded into registerAnnounceLeg, which fires on
the same transition, because a leg is a one-shot DELIVERY with retry and
classification while a post hook maintains idempotent STATE, runs on delete as
well as save, and refreshes silently on an edit.

Also fixes a real loader defect the extraction exposed: schema table names were
matched against the RAW file, so a fragment whose header says "every CREATE
TABLE carries IF NOT EXISTS" was rejected for a prefix violation on a table
called `carries`. module-uo's fragment hit exactly that. Both scans now read
split statements, which strip comments -- the same class of bug as a boundary
check failing on its own documentation.

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

server/db/data/spawnAtlas.art.example.json

@@ -1,24 +0,0 @@
-{
-  "_comment": [
-    "OPTIONAL operator-supplied creature art for the spawn atlas. Copy this file to",
-    "spawnAtlas.art.json (same directory) and edit it, then restart the server or run",
-    "`npm run atlas:import` — the art map is read on every atlas refresh.",
-    "",
-    "This project ships NO creature artwork and never will. UO sprites live in your",
-    "own client's .mul/.uop files and are yours to extract, not ours to redistribute.",
-    "If you want art on the atlas pages, export it yourself (UOFiddler, ClassicUO's",
-    "tooling, or any art extractor), drop the images under server/uploads/atlas/, and",
-    "map each creature slug to its file name here.",
-    "",
-    "Both spawnAtlas.art.json and server/uploads/ are gitignored, so neither the map",
-    "nor the images can be committed by accident.",
-    "",
-    "Keys are creature slugs, as reported by the atlas API and derived from the type",
-    "names in your own shard's Spawns/*.xml. Values are file names relative to",
-    "server/uploads/atlas/. Any creature with no entry here simply renders without",
-    "art — that is the default and fully supported state, not a degraded one."
-  ],
-  "lizardman": "lizardman.png",
-  "orc": "orc.png",
-  "dragon": "dragon.png"
-}