Feat v0.7.7 API tokens + extension permissions (#61)

Personal access tokens (PATs) for programmatic API access with
SHA-256 hashing, permission scoping (git model), and Settings/Admin UI.
Extension-declared user permissions with dynamic registry, gate_permission
manifest field, permissions Starlark module, and grouped admin UI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/store/postgres/stores.go

@@ -33,5 +33,6 @@ func NewStores(db *sql.DB) store.Stores {
 		Triggers:       NewTriggerStore(),
 		ScheduledTasks: NewScheduledTaskStore(),
 		Cluster:        NewClusterStore(),
+		APITokens:      NewAPITokenStore(db),
 	}
 }