fix: signature learning never skips support@/info@/admin@ senders (#1773)

src/builtin_actions.py

@@ -956,6 +956,17 @@ async def action_mark_email_boundaries(owner: str, **kwargs) -> Tuple[str, bool]
         return str(e), False
 
 
+# Sender local-parts (matched exactly or by prefix) whose mail never carries a
+# personal signature worth learning. These compare against the local-part
+# (before "@"), so role names must NOT include a trailing "@" — "support@" etc.
+# could never match a local-part of "support" and were silently dead.
+_SIG_SKIP_PREFIXES = (
+    "noreply", "no-reply", "donotreply", "do-not-reply",
+    "mailer-daemon", "notifications", "notification", "bounce",
+    "newsletter", "support", "info", "admin",
+)
+
+
 async def action_learn_sender_signatures(owner: str, **kwargs) -> Tuple[str, bool]:
     """For each sender with ≥3 recent inbox emails, ask the LLM to extract
     the common signature block across their messages. The cached sig is
@@ -1013,16 +1024,11 @@ async def action_learn_sender_signatures(owner: str, **kwargs) -> Tuple[str, boo
             return "No emails to scan", True
 
         # 2. Group by sender; drop addresses that don't carry useful sigs.
-        SKIP_PREFIXES = (
-            "noreply", "no-reply", "donotreply", "do-not-reply",
-            "mailer-daemon", "notifications", "notification", "bounce",
-            "newsletter", "support@", "info@", "admin@",
-        )
         by_sender: dict[str, list[dict]] = {}
         for m in mails:
             addr = m["from_address"]
             local = addr.split("@", 1)[0]
-            if any(local == p or local.startswith(p) for p in SKIP_PREFIXES):
+            if any(local == p or local.startswith(p) for p in _SIG_SKIP_PREFIXES):
                 continue
             # Skip plus-aliases / list-style addresses too.
             if "+" in local or "-noreply" in addr or "-bounces" in addr: