feat(rust): the permission manager — the site owns the whole store (D160-D163, D188-D198)

PLAN_REDESIGNS section 1.

- Every sync reads the store (perm.inventory), reconciles it against the
  site's record and its ledger, and pushes. A change made in the game is
  settled by the server's policy (D161): auto-adopt (default), adopt, or
  revoke. The first read of a server imports everything (D198).
- Groups belong to one server unless an admin shares them (D189), in new
  id-keyed tables; the old ones are copied once at boot and left unread.
  Holders may be a Steam account nobody linked (D188).
- An in-game change affects that server only (D190): a grant that reaches
  further gains an exception, a shared group is split.
- Never judged: a permission the server does not register right now (an
  unloaded plugin is not a revocation), and a pair an event lease holds.
- A new admin API (server view, grant/revoke with everywhere-or-here,
  groups by id, share/split, members, drift answers) and a screen on
  PermissionsManager's flow with a state on every toggle (D162, D163, U-1).
- The announcement voice names a group by id; old name settings still read.

Walked on both rigs against the walk core: import on an existing install,
auto-adopt of a grant and a revoke, a fleet grant's exception, Kits
unloaded without loss, a shared group split, adopt and revoke policies.
Server 420/420, client 58/58, swagger, imports and route manifest current.

Refs #21

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

server/db/purge.sql

@@ -19,6 +19,17 @@
 -- it knows this module registered, because it is the side that knows which
 -- registrant owned what.
 
+-- The permission manager, rebuilt (PLAN_REDESIGNS §1). Children before
+-- `rust_permgroups`, which they reference.
+DROP TABLE IF EXISTS rust_perm_exceptions;
+DROP TABLE IF EXISTS rust_perm_steam_grants;
+DROP TABLE IF EXISTS rust_permgroup_chat;
+DROP TABLE IF EXISTS rust_permgroup_steam_members;
+DROP TABLE IF EXISTS rust_permgroup_members;
+DROP TABLE IF EXISTS rust_permgroup_permissions;
+DROP TABLE IF EXISTS rust_permgroup_servers;
+DROP TABLE IF EXISTS rust_permgroups;
+
 -- Phase 17. `rust_perm_group_chat` before `rust_perm_groups`, which it
 -- references; the rest of this phase is columns, which go with their tables.
 DROP TABLE IF EXISTS rust_perm_group_chat;