fix(auth): new OAuth accounts invisible to scheduler after dynamic registration

When new OAuth auth files are added while the service is running,
`applyCoreAuthAddOrUpdate` calls `coreManager.Register()` (which upserts
into the scheduler) BEFORE `registerModelsForAuth()`. At upsert time,
`buildScheduledAuthMeta` snapshots `supportedModelSetForAuth` from the
global model registry — but models haven't been registered yet, so the
set is empty. With an empty `supportedModelSet`, `supportsModel()`
always returns false and the new auth is never added to any model shard.

Additionally, when all existing accounts are in cooldown, the scheduler
returns `modelCooldownError`, but `shouldRetrySchedulerPick` only
handles `*Error` types — so the `syncScheduler` safety-net rebuild
never triggers and the new accounts remain invisible.

Fix:
1. Add `RefreshSchedulerEntry()` to re-upsert a single auth after its
   models are registered, rebuilding `supportedModelSet` from the
   now-populated registry.
2. Call it from `applyCoreAuthAddOrUpdate` after `registerModelsForAuth`.
3. Make `shouldRetrySchedulerPick` also match `*modelCooldownError` so
   the full scheduler rebuild triggers when all credentials are cooling
   down — catching any similar stale-snapshot edge cases.

sdk/cliproxy/auth/conductor.go

@@ -213,6 +213,26 @@ func (m *Manager) syncScheduler() {
 	m.syncSchedulerFromSnapshot(m.snapshotAuths())
 }
 
+// RefreshSchedulerEntry re-upserts a single auth into the scheduler so that its
+// supportedModelSet is rebuilt from the current global model registry state.
+// This must be called after models have been registered for a newly added auth,
+// because the initial scheduler.upsertAuth during Register/Update runs before
+// registerModelsForAuth and therefore snapshots an empty model set.
+func (m *Manager) RefreshSchedulerEntry(authID string) {
+	if m == nil || m.scheduler == nil || authID == "" {
+		return
+	}
+	m.mu.RLock()
+	auth, ok := m.auths[authID]
+	if !ok || auth == nil {
+		m.mu.RUnlock()
+		return
+	}
+	snapshot := auth.Clone()
+	m.mu.RUnlock()
+	m.scheduler.upsertAuth(snapshot)
+}
+
 func (m *Manager) SetSelector(selector Selector) {
 	if m == nil {
 		return
@@ -2038,6 +2058,10 @@ func shouldRetrySchedulerPick(err error) bool {
 	if err == nil {
 		return false
 	}
+	var cooldownErr *modelCooldownError
+	if errors.As(err, &cooldownErr) {
+		return true
+	}
 	var authErr *Error
 	if !errors.As(err, &authErr) || authErr == nil {
 		return false

sdk/cliproxy/service.go

@@ -312,6 +312,12 @@ func (s *Service) applyCoreAuthAddOrUpdate(ctx context.Context, auth *coreauth.A
 	// This operation may block on network calls, but the auth configuration
 	// is already effective at this point.
 	s.registerModelsForAuth(auth)
+
+	// Refresh the scheduler entry so that the auth's supportedModelSet is rebuilt
+	// from the now-populated global model registry. Without this, newly added auths
+	// have an empty supportedModelSet (because Register/Update upserts into the
+	// scheduler before registerModelsForAuth runs) and are invisible to the scheduler.
+	s.coreManager.RefreshSchedulerEntry(auth.ID)
 }
 
 func (s *Service) applyCoreAuthRemoval(ctx context.Context, id string) {