fix(bridge): ignore pre-start trigger comments

tests/unit/test_bridge_trigger.py

@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import os
 import sys
+from datetime import timedelta
 
 # bridge.py reads HMAC/DRONE/GITEA secret FILES at import; point them at /dev/null (readable, empty)
 # so the import works in a unit context — parse_trigger doesn't use any of them.
@@ -93,3 +94,13 @@ def test_find_existing_comment_matches_marker(monkeypatch):
 def test_find_existing_comment_none_when_absent(monkeypatch):
     monkeypatch.setattr(bridge, "list_comments", lambda fn, n: [{"id": 1, "body": "hello"}])
     assert bridge.find_existing_comment("org/repo", 5) is None
+
+
+def test_preexisting_comment_from_before_bridge_start_is_ignored():
+    created = (bridge._PROCESS_STARTED_AT - timedelta(minutes=5)).isoformat().replace("+00:00", "Z")
+    assert bridge._is_preexisting_comment({"created_at": created}) is True
+
+
+def test_comment_after_bridge_start_is_not_treated_as_preexisting():
+    created = (bridge._PROCESS_STARTED_AT + timedelta(minutes=5)).isoformat().replace("+00:00", "Z")
+    assert bridge._is_preexisting_comment({"created_at": created}) is False