feat(safety): report, block and hide, MODULE_API 1.21.0

USER_SAFETY.md step 2 (core), with S11-S14 decided while building it.

- Reports: POST /player/reports takes any target type, core's forum
  types or a module's registered ones. One resolver
  (model/safety/targets.js) answers "what is this item, for this
  reader" and 404s an item the reader cannot see. Every report stores
  content_reports.snapshot; the queue shows a module item from it.
- Hide for everyone: POST /admin/moderation/reports/:id/hide hides the
  item through its own moderation (forum hide as staff, or the module's
  hide) and actions the report with actioned_with = 'hide'.
- Blocks (user_blocks) name an item, never a person, and land on the
  author's account first (S12); an unlinked game identity is blocked as
  itself and becomes an account block once linked (S14). Staff cannot
  be blocked; a block on someone later promoted stops applying (S8).
- Hide for me (user_hidden_items), /auth/me/blocks and /auth/me/hidden.
- Forum reads filter blocked authors and hidden items on the server and
  carry canBlock per thread and post.
- MODULE_API 1.21.0: api.registerReportTargets,
  api.registerGameIdentities, ctx.safety.forViewer and
  ctx.safety.staffAmong, so a module filters its own per-viewer feeds on
  the server (S11) and marks lines canBlock (S13).
- Web: Hide for me / Block author in the forum menus, a Blocked section
  on both account pages, Hide for everyone in the Reports queue.
- Tests, OpenAPI, route/guard/engagement manifests regenerated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

server/routes.guards.json

@@ -818,6 +818,17 @@
         "validate"
       ]
     },
+    {
+      "method": "POST",
+      "path": "/api/v1/admin/moderation/reports/:id/hide",
+      "handlers": 4,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
     {
       "method": "GET",
       "path": "/api/v1/admin/moderation/search",
@@ -1928,6 +1939,37 @@
         "validate"
       ]
     },
+    {
+      "method": "GET",
+      "path": "/api/v1/auth/me/blocks",
+      "handlers": 1,
+      "gates": [
+        "noindex",
+        "requireAuth"
+      ]
+    },
+    {
+      "method": "POST",
+      "path": "/api/v1/auth/me/blocks",
+      "handlers": 5,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
+    {
+      "method": "DELETE",
+      "path": "/api/v1/auth/me/blocks/:id",
+      "handlers": 4,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
     {
       "method": "GET",
       "path": "/api/v1/auth/me/devices",
@@ -1959,6 +2001,46 @@
         "validate"
       ]
     },
+    {
+      "method": "DELETE",
+      "path": "/api/v1/auth/me/hidden",
+      "handlers": 2,
+      "gates": [
+        "noindex",
+        "requireAuth"
+      ]
+    },
+    {
+      "method": "GET",
+      "path": "/api/v1/auth/me/hidden",
+      "handlers": 1,
+      "gates": [
+        "noindex",
+        "requireAuth"
+      ]
+    },
+    {
+      "method": "POST",
+      "path": "/api/v1/auth/me/hidden",
+      "handlers": 5,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
+    {
+      "method": "DELETE",
+      "path": "/api/v1/auth/me/hidden/:targetType/:targetId",
+      "handlers": 5,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
     {
       "method": "GET",
       "path": "/api/v1/auth/me/notifications",
@@ -2297,6 +2379,17 @@
         "requireAuth"
       ]
     },
+    {
+      "method": "POST",
+      "path": "/api/v1/player/reports",
+      "handlers": 7,
+      "gates": [
+        "noindex",
+        "requireAuth",
+        "middleware",
+        "validate"
+      ]
+    },
     {
       "method": "GET",
       "path": "/api/v1/player/teams",