feat(champ): stream champion-spawn state to the sidecar board

Champion spawns have no ServUO EventSink, so add a fourth polled stream
(BridgeChamps) modeled on BridgeSweeps: enumerate every spawn each tick,
fold to a small record, and emit champ.update only on change. No core
patch — every field used is public.

Covers all three families via a `category` field:
  - champion: ChampionSpawn (type/level/kills/boss/cooldown ETA)
  - mini:     MiniChamp (type/level; auto-restarts, no kill counter)
  - sea:      BaseSeaChampion (a High Seas world-boss mobile, alive only
              while summoned; removed via champ.remove when slain)

Status folds to active/cooldown/dormant. A (re)connection clears the diff
cache so the next sweep re-emits the full board, rebuilding a sidecar that
restarted on its own. Transient entries leave via champ.remove.

Sidecar: a `champs` current-state table (one row per serial) fed by
champ.update (upsert) and champ.remove (delete), exposed at GET /champs as
the live board. New ChampSweepSeconds config (default 10s), wired into
[bridge reload/sweepnow/status. Documented in docs/INTEGRATION.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0114TpmrNW4wNXsHq5CR72jQ

overlay/Scripts/Custom/Bridge/BridgeBoot.cs

@@ -160,6 +160,7 @@ namespace Server.Custom.Bridge
                     BridgeConfig.Load();
                     BridgeSweeps.Rearm();
                     BridgePages.Rearm();
+                    BridgeChamps.Rearm();
                     e.Mobile.SendMessage("Bridge: {0}", BridgeConfig.Describe());
                     e.Mobile.SendMessage("Bridge: sweeps re-armed; endpoint changes take effect on reconnect.");
                     break;
@@ -171,8 +172,10 @@ namespace Server.Custom.Bridge
 
                 case "sweepnow":
                     BridgeSweeps.SweepOnce();
+                    BridgeChamps.SweepOnce();
                     e.Mobile.SendMessage("Bridge: ran one sweep of each stream.");
                     e.Mobile.SendMessage("Bridge: {0}", BridgeSweeps.Status());
+                    e.Mobile.SendMessage("Bridge: {0}", BridgeChamps.Status());
                     break;
 
                 default:
@@ -182,6 +185,7 @@ namespace Server.Custom.Bridge
                         BridgeLink.Connected, BridgeLink.Depth, BridgeLink.Sent, BridgeLink.Dropped,
                         BridgeLink.Received, BridgeLink.Connects, BridgeLink.WriteErrors);
                     e.Mobile.SendMessage("Bridge: {0}", BridgeSweeps.Status());
+                    e.Mobile.SendMessage("Bridge: {0}", BridgeChamps.Status());
                     e.Mobile.SendMessage("Bridge: {0}", BridgePages.Status());
                     break;
             }