feat(rust): Teams from first-party clans (phase 9, protocol 6)

A first-party Rust clan is a Team (R5). This module becomes the site's
Team provider and answers core from the plugin's `clans` board. Design
of record: docs/modules/rust/PLAN.md §24, D47-D58.

- The store: rust_clans, rust_clan_members and rust_clan_boards. A clan's
  identity is <serverId>:<clanId>:<createdMs> (D52), because the game
  restarts clan ids whenever its clan database version changes.
- The provider (D53): getTeams is complete only when every server's
  board is fresh, supported and untruncated. It is partial when some
  are, and refuses when none are. Freshness is judged by the website's
  clock, from when the board's `t` last advanced.
- Only a complete board may mark a clan gone. A board at the game's
  100-clan ceiling (D55), or one with an unreadable row, proves nothing
  about what it leaves out.
- Leadership is diffed board to board and published (D54). The five clan
  events are published as team.* kinds, and written to the Team feed as
  members-only lines (D49).
- Core only writes feed items for a Team it already holds. So the last 10
  minutes of clan events are re-offered on each board refresh, deduped by
  a sha1 key: core clamps a dedupeKey to 40 characters, and a readable key
  would be truncated into collisions.
- projectRoster and the clan page share one audience rule (D48): the
  clan's linked members and staff by default, re-read from the users row.
  The setting lives on Admin > Rust visibility, which also warns about
  uMod Clans (D47) and the ceiling.
- Public: GET servers/:id/clans (the list is public, D58) and
  GET clans/:externalId. The client adds a Clans tab and
  /rust/clans/:externalId, with three module slots for core's notify,
  activity and forum contributions (D56).
- Linking and unlinking an account ask core to reconcile Teams (D57).
- The clan kinds are staff-class in the public feed allowlist.
- PROTOCOL_VERSION is now 6.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

server/router/admin/visibility.router.js

@@ -21,12 +21,13 @@ const { body } = core.validator
 const visibilityRouter = express.Router()
 
 const AUDIENCES = ['staff', 'signed_in', 'public']
+const CLAN_AUDIENCES = ['members', 'signed_in', 'public']
 
 visibilityRouter.get(
   '/',
   // #swagger.tags = ['Admin · Rust']
-  // #swagger.summary = 'Who may see who is online'
-  // #swagger.description = 'The fleet default and every server’s optional override. It governs the Online list, every feed item that names a player who was on the server (connects, respawns, deaths, chat, tallies) and the leaderboard’s `lastSeen`. The default is `staff`: nothing names who is online until an operator widens it. The player count is public at every setting.'
+  // #swagger.summary = 'Who may see who is online, and who may see a clan roster'
+  // #swagger.description = 'The presence fleet default and every server’s optional override. It governs the Online list, every feed item that names a player who was on the server (connects, respawns, deaths, chat, tallies) and the leaderboard’s `lastSeen`. The default is `staff`: nothing names who is online until an operator widens it. The player count is public at every setting. `clans` carries the clan roster audience (default `members`: the clan’s own linked members, and staff) and each server’s clan board — whether it is current, at the game’s 100-clan ceiling, or running the uMod Clans plugin, whose clans are not Teams.'
   /* #swagger.responses[200] = { description: 'The fleet default and each server', content: { "application/json": { schema: { $ref: "#/components/schemas/RustVisibility" } } } } */
   requireRole('admin'),
   visibility.read,
@@ -35,8 +36,8 @@ visibilityRouter.get(
 visibilityRouter.put(
   '/',
   // #swagger.tags = ['Admin · Rust']
-  // #swagger.summary = 'Change who may see who is online'
-  // #swagger.description = 'Sets the fleet default, one or more server overrides, or both. A server set to `null` follows the fleet default again. Validated whole before anything is written: a request naming a server that does not exist changes nothing.'
+  // #swagger.summary = 'Change who may see who is online, or who may see a clan roster'
+  // #swagger.description = 'Sets the presence fleet default, one or more server overrides, the clan roster audience, or any of them together. A server set to `null` follows the fleet default again. Validated whole before anything is written: a request naming a server that does not exist changes nothing. Widening the clan roster audience also shows which members are online to that audience, because a roster row carries it.'
   /* #swagger.requestBody = { required: true, content: { "application/json": { schema: { $ref: "#/components/schemas/RustVisibilityUpdate" } } } } */
   /* #swagger.responses[200] = { description: 'Saved; answers the new state', content: { "application/json": { schema: { $ref: "#/components/schemas/RustVisibility" } } } } */
   /* #swagger.responses[400] = { description: 'An audience that does not exist' } */
@@ -44,6 +45,7 @@ visibilityRouter.put(
   requireRole('admin'),
   body('fleet').optional().isIn(AUDIENCES).withMessage(`fleet must be one of ${AUDIENCES.join(', ')}`),
   body('servers').optional().isObject().withMessage('servers maps a server id to an audience or null'),
+  body('clanRoster').optional().isIn(CLAN_AUDIENCES).withMessage(`clanRoster must be one of ${CLAN_AUDIENCES.join(', ')}`),
   validate,
   visibility.update,
 )