test(dingtalk): cover get_connected_platforms + null platform_toolsets

Follow-ups to the salvaged commits in this PR:

* gateway/config.py — strip trailing whitespace from youngDoo's diff
  (line 315 had ~140 trailing spaces).

* hermes_cli/tools_config.py — replace `config.get("platform_toolsets", {})`
  with `config.get("platform_toolsets") or {}`. Handles the case where the
  YAML key is present but explicitly null (parses as None, previously
  crashed with AttributeError on the next line's .get(platform)).
  Cherry-picked from yyq4193's #9003 with attribution.

* tests/gateway/test_config.py — 4 new tests for TestGetConnectedPlatforms
  covering DingTalk via extras, via env vars, disabled, and missing creds.

* tests/hermes_cli/test_tools_config.py — regression test for the null
  platform_toolsets edge case.

* scripts/release.py — add kagura-agent, youngDoo, yyq4193 to AUTHOR_MAP.

Co-authored-by: yyq4193 <39405770+yyq4193@users.noreply.github.com>

gateway/config.py

@@ -312,7 +312,7 @@ class GatewayConfig:
                 config.extra.get("client_id") or os.getenv("DINGTALK_CLIENT_ID")
             ) and (
                 config.extra.get("client_secret") or os.getenv("DINGTALK_CLIENT_SECRET")
-            ):                                                                                                                                                                                    
+            ):
                 connected.append(platform)
         
         return connected