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>

docs/PROTOCOL_2.md

@@ -380,7 +380,7 @@ If the website mirrors rosters/links (it does — `store.record_link`), it must
 
 ## 13. Part B phasing
 
-1. **Guilds + governors.** `BridgeSocial.cs` (guild sweep + `JoinGuild`) and `BridgeGovernance.cs` (city sweep), their `GuildSweepSeconds`/`CitySweepSeconds` config, and the `world.systems` frame. Ship with their REST snapshots (`GET /guilds`, `/governors`, §12.2) from day one — a diff stream without its snapshot is half-built.
+1. ~~**Guilds + governors.**~~ **Built (2026-07-17), compiles clean both sides.** `BridgeSocial.cs` (guild sweep + `JoinGuild` → `guild.update`/`guild.remove`/`guild.join`) and `BridgeGovernance.cs` (city sweep → `city.update`, gated on `CityLoyaltySystem.Enabled`), `GuildSweepSeconds` (60s) / `CitySweepSeconds` (300s) config, both wired into `[bridge reload|sweepnow|status`. Sidecar `guilds`/`governors` board tables + `GET /guilds`, `/governors` served from the store (the §12.2 snapshot rule). Shared `BridgeJson.Actor` writer (serial/name/acct/webId/player). **Deviation from the §10 sketch:** the wire uses full-state `guild.update`/`city.update` upserts (website derives "created"/"governor changed" from the board) rather than discrete `guild.created`/`city.governor` events — this avoids a reconnect re-emit looking like a storm of creations, matching the proven `champ.update` model. *Live end-to-end run still pending.*
 2. **Presence.** Who's-online/population sweep + region presence (`OnEnterRegion`) → `GET /online`, population history in the store.
 3. **Housing registry.** Extend the decay sweep to a full owner→houses list + houses-for-sale → `GET /houses`. (Selected from the §11 menu.)
 4. **Titles.** `char.profile` `titles` block (§10.3) — no new stream, folds into `BridgeProfile`.