feat(permissions): richer channel-approval flow with agent selection and free-text naming

Replace the hardcoded Approve/Ignore card with a multi-step flow:
- Single agent: "Connect to [name]" / "Connect new agent" / "Reject"
- Multiple agents: "Choose existing agent" (follow-up list) / "Connect new agent" / "Reject"
- "Connect new agent" prompts for a free-text name via DM, creates immediately on reply
- Add setMessageInterceptor router hook for capturing free-text replies
- Add resolveChannelName optional method to ChannelAdapter interface

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

src/modules/permissions/db/pending-channel-approvals.ts

@@ -51,6 +51,12 @@ export function hasInFlightChannelApproval(messagingGroupId: string): boolean {
   return row !== undefined;
 }
 
+export function updatePendingChannelApprovalCard(messagingGroupId: string, title: string, optionsJson: string): void {
+  getDb()
+    .prepare('UPDATE pending_channel_approvals SET title = ?, options_json = ? WHERE messaging_group_id = ?')
+    .run(title, optionsJson, messagingGroupId);
+}
+
 export function deletePendingChannelApproval(messagingGroupId: string): void {
   getDb().prepare('DELETE FROM pending_channel_approvals WHERE messaging_group_id = ?').run(messagingGroupId);
 }