test(dingtalk): cover require_mention + allowed_users gating

Adds 16 regression tests for the gating logic introduced in the
salvaged commit:

  * TestAllowedUsersGate — empty/wildcard/case-insensitive matching,
    staff_id vs sender_id, env var CSV population
  * TestMentionPatterns — compilation, case-insensitivity, invalid
    regex is skipped-not-raised, JSON env var, newline fallback
  * TestShouldProcessMessage — DM always accepted, group gating via
    require_mention / is_in_at_list / wake-word pattern / free_response_chats

Also adds yule975 to scripts/release.py AUTHOR_MAP (release CI blocks
unmapped emails).

scripts/release.py

@@ -84,6 +84,7 @@ AUTHOR_MAP = {
     "abdullahfarukozden@gmail.com": "Farukest",
     "lovre.pesut@gmail.com": "rovle",
     "kevinskysunny@gmail.com": "kevinskysunny",
+    "xiewenxuan462@gmail.com": "yule975",
     "hakanerten02@hotmail.com": "teyrebaz33",
     "ruzzgarcn@gmail.com": "Ruzzgar",
     "alireza78.crypto@gmail.com": "alireza78a",