feat(shard): ingest world.ruleset and publish it at /site/rules

Protocol 3.0 §5 (docs/link/v3.md). The shard publishes its own ruleset —
expansion, which optional systems are on, skill/stat caps, account and house
limits, champion scroll rules, the save/restart schedule — and the site renders
it, so the rules page cannot drift from how the shard actually plays.

Server
  - shard_ruleset: a singleton table (id = 1) holding the whole frame in
    `payload`, with `rev` and `expansion` hoisted. Nothing is normalized out:
    the frame is a flat description of config read as one page, and splitting it
    into columns would mean a schema change every time the shard grows a block.
  - shardIngest routes world.ruleset to setRuleset and deliberately does NOT
    log it — the shard re-emits the whole ruleset on every sidecar connect, so
    logging would append a duplicate row per reconnect, and server.hello already
    marks each of those.
  - uoLinkSocket backfills GET /ruleset explicitly rather than via snapshot(),
    which asserts an array; this covers the order where the sidecar was already
    up and holding the ruleset when we reconnected.
  - GET /public/shard/ruleset behind requireFeature('ruleset') and projected,
    per §3.6.1's rule that a shard read which doesn't project is a bug. `null`
    means the shard has never published one — a real answer, distinct from a
    published ruleset, and the page says so.

Client
  - routes/public/Rules.jsx at /site/rules, live via world.ruleset (a frame is a
    complete ruleset, not a delta, so the newest one wins outright). Caps are
    rendered from tenths — 7000 is 700.0, and showing the raw number would
    mislead. A systems key this build doesn't know still renders, humanised, so
    a newer plugin can't go invisible against an older client.
  - Nav entry gated on the `ruleset` feature, so it hides rather than 403s.

Verified end to end against the local MariaDB and a sidecar fed by a fake shard:
backfill snapshot, live SSE delivery of a changed ruleset, REST reflecting the
overwrite, an empty /feed (not logged), and the gate — 200 by default, 403 at
audience=staff (and dropped from /features so nav hides it), 404 when disabled.
Page rendered clean at all breakpoints checked, no console errors.

497 server tests pass; routes.manifest.json, routes.guards.json and the OpenAPI
spec regenerated.

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

server/swagger/swagger-output.json

@@ -11335,6 +11335,38 @@
         }
       }
     },
+    "/api/v1/public/shard/ruleset": {
+      "get": {
+        "tags": [
+          "Public · Shard"
+        ],
+        "summary": "The shard\\'s published ruleset (expansion, systems, caps, limits)",
+        "description": "How this shard is actually configured, published by the shard itself as one world.ruleset frame: expansion, which optional systems are on, skill/stat caps, account and house limits, champion scroll rules and the save/restart schedule. Served from our own store, so it renders while the shard is down; live via world.ruleset on /shard/stream. Returns `null` if the shard has never published one (an older plugin, or Bridge.RulesetEnabled=false) — distinct from a published ruleset, and the page renders it differently.",
+        "responses": {
+          "200": {
+            "description": "The ruleset, or null if never published",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "nullable": true,
+                  "additionalProperties": true
+                }
+              }
+            }
+          },
+          "403": {
+            "description": "Forbidden"
+          },
+          "404": {
+            "description": "Not Found"
+          },
+          "500": {
+            "description": "Internal Server Error"
+          }
+        }
+      }
+    },
     "/api/v1/public/shard/status": {
       "get": {
         "tags": [