feat(protocol2): guild and town-governor world-state streams (Part B ph.1)

Adds the first Part B streams from docs/PROTOCOL_2.md: guild rosters and
town governors ("mayors"), both outbound diff-board sweeps mirroring the
existing champ board.

Overlay:
- BridgeSocial (new): guild sweep+diff over BaseGuild.List -> guild.update /
  guild.remove (full-state upsert; disband detected via Disbanded), plus a
  real-time guild.join from EventSink.JoinGuild. (EventSink.CreateGuild is only
  the load-time factory, so creation is derived sidecar-side from a first-seen
  id, as champs do.)
- BridgeGovernance (new): city sweep over CityLoyaltySystem.Cities -> city.update
  (governor / governor-elect / election phase), gated on CityLoyaltySystem.Enabled.
- BridgeJson.Actor: shared serial/name/acct/webId/player writer used by both.
- BridgeConfig: GuildSweepSeconds (60s), CitySweepSeconds (300s).
- BridgeBoot: both wired into [bridge reload|sweepnow|status.

Sidecar:
- store: guilds + governors board tables with upsert/delete/all.
- main: route guild.update/remove and city.update into the boards.
- web: GET /guilds, GET /governors served from the store (snapshot-companion
  rule, so a fresh page or a restarted sidecar hydrates without the shard).

Docs: INTEGRATION.md event catalog (guild.*, city.update) + board endpoints;
PROTOCOL_2.md Part B phase 1 marked built.

Verified: sidecar cargo check clean; overlay compiles in the full ServUO
Scripts tree (0 errors, 0 warnings). Live end-to-end run still pending.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

overlay/Scripts/Custom/Bridge/BridgeBoot.cs

@@ -161,6 +161,8 @@ namespace Server.Custom.Bridge
                     BridgeSweeps.Rearm();
                     BridgePages.Rearm();
                     BridgeChamps.Rearm();
+                    BridgeSocial.Rearm();
+                    BridgeGovernance.Rearm();
                     e.Mobile.SendMessage("Bridge: {0}", BridgeConfig.Describe());
                     e.Mobile.SendMessage("Bridge: sweeps re-armed; endpoint changes take effect on reconnect.");
                     break;
@@ -173,9 +175,13 @@ namespace Server.Custom.Bridge
                 case "sweepnow":
                     BridgeSweeps.SweepOnce();
                     BridgeChamps.SweepOnce();
+                    BridgeSocial.SweepOnce();
+                    BridgeGovernance.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());
+                    e.Mobile.SendMessage("Bridge: {0}", BridgeSocial.Status());
+                    e.Mobile.SendMessage("Bridge: {0}", BridgeGovernance.Status());
                     break;
 
                 default:
@@ -186,6 +192,8 @@ namespace Server.Custom.Bridge
                         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}", BridgeSocial.Status());
+                    e.Mobile.SendMessage("Bridge: {0}", BridgeGovernance.Status());
                     e.Mobile.SendMessage("Bridge: {0}", BridgePages.Status());
                     break;
             }