fix(presentation): extract 12 handler violations to use cases

- TokenService port + JwtTokenService adapter; login/refresh return LoginResult
- delete get_token (dup of login); create_tokens helper removed
- type UpdateChannelRequest schedule_config/recycle_policy (no serde_json::Value)
- update_settings returns updated Vec; handler calls one use case
- config use case in application::config; handler maps DTO only
- SyncStatusEntry moved to api-types w/ From<LibrarySyncLogEntry>
- trigger_sync: Conflict error, drop sync_trigger.send from handler
- UpsertProviderCommand.config accepts Value; serialization in use case
- get_current_broadcast returns BroadcastWithChannel; one call
- get_stream_url resolves broadcast internally; handler single call

crates/mcp/src/tools/schedule.rs

@@ -35,10 +35,10 @@ pub async fn get_active_schedule(deps: &Arc<ScheduleDeps>, channel_id: Uuid) ->
 pub async fn get_current_broadcast(deps: &Arc<ScheduleDeps>, channel_id: Uuid) -> String {
     let query = GetCurrentBroadcastQuery { channel_id };
     match application::schedule::get_current_broadcast::execute(deps, query).await {
-        Ok(Some(b)) => {
-            let offset = b.offset_secs();
+        Ok(Some(result)) => {
+            let offset = result.broadcast.offset_secs();
             ok_json(&CurrentBroadcastDto {
-                slot: b.into_slot(),
+                slot: result.broadcast.into_slot(),
                 offset_secs: offset,
             })
         }