fix: address the 15 CodeRabbit findings from the wire-audit review

Security:
- roomcode PUT now requires instance ownership (any player could plant
  or relocate codes on foreign private instances)
- /platformid/{accountId} requires auth (anonymous Steam/Oculus id
  enumeration oracle)
- request tracing no longer captures successful /thread bodies by
  default (chat messages landed unredacted in logs); opt in via
  Trace__SuccessBodyPaths
- anonymous action-link renewal clamped to 720h per consume

Data integrity:
- buyPurchaseReminder upserts its objective sentinel (second purchase
  threw UNIQUE after the wallet was debited)
- progression reward gift + idempotency sentinel commit in one
  transaction (crash between them double-minted the reward)
- ClubPermissionsGalleryAndModeration migration defaults corrected to
  the entity contract (CommentsJson '[]', ClubChatEnabled true); new
  one-shot ClubChatDefaultRepair migration fixes databases that
  applied the wrong defaults; bootstrap repairs '' CommentsJson rows
- admin subroom-maxplayers audit entry commits with the mutation
- account purge covers CustomAvatarItems (ownership deleted, created
  items reassigned to the system account)
- duplicate photo reports ignored while one is unresolved

Stability:
- bootstrap only swallows the expected duplicate-column error; locked
  databases and schema failures now fail startup instead of the first
  endpoint
- clone blob write failure degrades to an empty sub-room instead of a
  500 after the clone row committed
- resumed photo-feed cursor stamped DateTimeKind.Utc (Npgsql rejects
  Unspecified for timestamptz)
- unreadcounts queries per requested room instead of materialising the
  whole comment keyspace

Tests:
- destroys-the-probe-session template guard is case-insensitive

74/74 tests pass.

DorkNet.Server.Tests/GameClientEndpointContractTests.cs

@@ -66,8 +66,13 @@ public sealed class GameClientEndpointContractTests :
         if (!string.Equals(route.Method, "DELETE", StringComparison.OrdinalIgnoreCase))
             return false;
 
+        // Case-insensitive to match the method comparison above: a route
+        // declared "Account/v1/me" would otherwise slip through and delete
+        // the probe player mid-run.
         var template = route.Template.Trim('/');
-        return template is "account/me" or "account/v1/me" or "account/v2/me";
+        return template.Equals("account/me", StringComparison.OrdinalIgnoreCase)
+            || template.Equals("account/v1/me", StringComparison.OrdinalIgnoreCase)
+            || template.Equals("account/v2/me", StringComparison.OrdinalIgnoreCase);
     }
 
     private static async Task<EndpointProbeResult> ProbeAsync(