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>

link/INTEGRATION.md

@@ -239,6 +239,47 @@ Category-specific fields on `champ.update`:
 
 The events are live deltas; for the current board of all spawns at once, use `GET /champs` (§6) — that's what you render on connect, then keep live with these events.
 
+#### Guilds (Protocol 2.0)
+
+Guilds expose only one in-game event (a member joining), so the roster is polled (`GuildSweepSeconds`, default 60s) and diffed. Like champion spawns, `guild.update` is a **full-state upsert** emitted only on change — treat a guild id you've never seen as "newly created", and drop one on `guild.remove`. `guild.join` is the one real-time event, on top of the board.
+
+| kind | fields | notes |
+|------|--------|-------|
+| `guild.update` | `id`, `name`, `abbr`, `members`, `online`, `alliance` (or null), `leader` (actor object or null) | A guild's roster/leader/alliance changed, or its first sight this connection. A **leave** shows up here as `members` dropping. |
+| `guild.remove` | `id` | The guild disbanded (leader gone) or was removed. Drop the row. |
+| `guild.join` | `id`, `name`, `abbr`, `who` (actor object) | Real-time: a player joined a guild (`EventSink.JoinGuild`). |
+
+The `leader`/`who` **actor object** is `{serial, name, acct?, webId?, player}` — `acct`/`webId` present when the mobile has an account / a linked website user.
+
+```json
+{"kind":"guild.update","id":1042,"name":"The Silver Hand","abbr":"TSH","members":14,
+ "online":3,"alliance":"Britannian Pact",
+ "leader":{"serial":"0x1A2B","name":"Darrow","acct":"whitlocktech","webId":"9931","player":true},
+ "t":1752489280000}
+{"kind":"guild.join","id":1042,"name":"The Silver Hand","abbr":"TSH",
+ "who":{"serial":"0x77","name":"Bran","acct":"bran","player":true},"t":1752489281000}
+```
+
+Render the current board from `GET /guilds` (§6) on connect, then keep it live with these events.
+
+#### Town governors (Protocol 2.0)
+
+In modern ServUO the "mayor" of a town is the **City Loyalty Governor**. The set of cities is polled (`CitySweepSeconds`, default 300s); each city emits `city.update` (full-state upsert) only when its governor, governor-elect, or election phase changes. **No events at all unless the shard runs the City Loyalty system.**
+
+| kind | fields | notes |
+|------|--------|-------|
+| `city.update` | `city`, `governor` (actor or null), `governorElect` (actor or null), `electionPhase`, `candidates`, `autoPickAt` (ISO-8601 UTC, when an election is ongoing) | A city's governance changed. Derive "the governor changed" by comparing to your stored board. |
+
+`electionPhase` is one of `none` / `nominate` / `vote` / `pending`. Cities: Moonglow, Britain, Jhelom, Yew, Minoc, Trinsic, SkaraBrae, NewMagincia.
+
+```json
+{"kind":"city.update","city":"Britain","electionPhase":"none","candidates":0,
+ "governor":{"serial":"0x1A2B","name":"Darrow","acct":"whitlocktech","webId":"9931","player":true},
+ "governorElect":null,"t":1752489280000}
+```
+
+Render the current board from `GET /governors` (§6) on connect, then keep it live with these events.
+
 ---
 
 ## 5. REST — read queries
@@ -512,6 +553,29 @@ GET /champs
 
 A row survives a sidecar restart (it's in SQLite), so the board reflects the last-known state even during a shard outage. A `sea` boss appears when summoned and is removed when slain.
 
+### Guild board (Protocol 2.0)
+
+```
+GET /guilds
+→ { "guilds": [ {"kind":"guild.update","id":1042,"name":"The Silver Hand","abbr":"TSH",
+      "members":14,"online":3,"alliance":"Britannian Pact",
+      "leader":{"serial":"0x1A2B","name":"Darrow","acct":"whitlocktech","webId":"9931","player":true},
+      "t":1752489280000}, ... ] }
+```
+
+Every guild's latest roster snapshot at once — the live board. Served from the sidecar's projection (no shard round-trip), kept current by the `guild.*` stream (§4). Render on load, then subscribe. Each entry is exactly a `guild.update` payload; ordered by name. Survives a sidecar restart.
+
+### Governor board (Protocol 2.0)
+
+```
+GET /governors
+→ { "cities": [ {"kind":"city.update","city":"Britain","electionPhase":"none","candidates":0,
+      "governor":{"serial":"0x1A2B","name":"Darrow","acct":"whitlocktech","player":true},
+      "governorElect":null,"t":1752489280000}, ... ] }
+```
+
+Every city's latest governance snapshot — the live board, kept current by the `city.update` stream (§4). Empty if the shard does not run the City Loyalty system. Ordered by city.
+
 ---
 
 ## 7. Status codes