feat(python/robomp): added followup thread context to comment handling

- Normalized reviewer-bot matching by stripping a trailing `[bot]` suffix when resolving configured bot logins.
- Fetched PR thread history for followup comments without directives and carried it through task execution.
- Updated followup prompt rendering to include prior conversation context for handle_comment tasks.

python/robomp/tests/test_server.py

@@ -1610,7 +1610,7 @@ async def test_handle_pr_conversation_unmapped_bot_pr_uses_pr_branch(
     settings: Settings, tmp_path: Path, stub_run_task, monkeypatch
 ) -> None:
     from robomp import tasks
-    from robomp.github_client import IssueInfo, PullRequestInfo, RepoInfo
+    from robomp.github_client import CommentInfo, IssueInfo, PullRequestInfo, RepoInfo
 
     sandbox = _RecordingSandbox(tmp_path)
     db = get_database(settings.sqlite_path)
@@ -1652,9 +1652,27 @@ async def test_handle_pr_conversation_unmapped_bot_pr_uses_pr_branch(
         assert number == 900
         return pr_issue
 
+    async def _list_comments(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return [CommentInfo(id=77, author="can1357", body="prior PR context", created_at="2026-05-14T00:00:00Z")]
+
+    async def _list_review_comments(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return []
+
+    async def _list_pr_reviews(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return []
+
     monkeypatch.setattr(GitHubClient, "get_pull_request", _get_pull_request)
     monkeypatch.setattr(GitHubClient, "get_repo", _get_repo)
     monkeypatch.setattr(GitHubClient, "get_issue", _get_issue)
+    monkeypatch.setattr(GitHubClient, "list_comments", _list_comments)
+    monkeypatch.setattr(GitHubClient, "list_review_comments", _list_review_comments)
+    monkeypatch.setattr(GitHubClient, "list_pr_reviews", _list_pr_reviews)
 
     payload = {
         "action": "created",
@@ -1677,6 +1695,10 @@ async def test_handle_pr_conversation_unmapped_bot_pr_uses_pr_branch(
     assert call["task_kind"] == "handle_comment"
     assert call["pr_number"] == 900
     assert call["inputs"].issue.is_pull_request is True
+    assert [(m.kind, m.author, m.body) for m in call["thread"]] == [
+        ("pr_body", settings.bot_login, "PR body"),
+        ("comment", "can1357", "prior PR context"),
+    ]
     assert sandbox.ensure_calls[0]["number"] == 900
     assert sandbox.ensure_calls[0]["existing_branch"] == "farm/abc12345/fix-flaky-parser"
     row = db.get_issue("octo/widget#900")
@@ -1690,7 +1712,7 @@ async def test_handle_pr_conversation_repairs_missing_pr_mapping_from_branch(
     settings: Settings, tmp_path: Path, stub_run_task, monkeypatch
 ) -> None:
     from robomp import tasks
-    from robomp.github_client import IssueInfo, PullRequestInfo, RepoInfo
+    from robomp.github_client import CommentInfo, IssueInfo, PullRequestInfo, RepoInfo
 
     sandbox = _RecordingSandbox(tmp_path)
     db = get_database(settings.sqlite_path)
@@ -1709,6 +1731,16 @@ async def test_handle_pr_conversation_repairs_missing_pr_mapping_from_branch(
         labels=(),
         is_pull_request=False,
     )
+    pr_issue = IssueInfo(
+        repo="octo/widget",
+        number=900,
+        title="Fix flaky parser",
+        body="PR body",
+        state="open",
+        author=settings.bot_login,
+        labels=(),
+        is_pull_request=True,
+    )
     pr_info = PullRequestInfo(
         repo="octo/widget",
         number=900,
@@ -1731,12 +1763,33 @@ async def test_handle_pr_conversation_repairs_missing_pr_mapping_from_branch(
 
     async def _get_issue(self, repo_full: str, number: int):
         assert repo_full == "octo/widget"
-        assert number == 42
-        return issue
+        if number == 42:
+            return issue
+        if number == 900:
+            return pr_issue
+        raise AssertionError(number)
+
+    async def _list_comments(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return [CommentInfo(id=78, author="can1357", body="prior PR context", created_at="2026-05-14T00:00:00Z")]
+
+    async def _list_review_comments(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return []
+
+    async def _list_pr_reviews(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return []
 
     monkeypatch.setattr(GitHubClient, "get_pull_request", _get_pull_request)
     monkeypatch.setattr(GitHubClient, "get_repo", _get_repo)
     monkeypatch.setattr(GitHubClient, "get_issue", _get_issue)
+    monkeypatch.setattr(GitHubClient, "list_comments", _list_comments)
+    monkeypatch.setattr(GitHubClient, "list_review_comments", _list_review_comments)
+    monkeypatch.setattr(GitHubClient, "list_pr_reviews", _list_pr_reviews)
 
     payload = {
         "action": "created",
@@ -1758,6 +1811,10 @@ async def test_handle_pr_conversation_repairs_missing_pr_mapping_from_branch(
     call = stub_run_task[0]
     assert call["inputs"].issue.number == 42
     assert call["pr_number"] == 900
+    assert [(m.kind, m.author, m.body) for m in call["thread"]] == [
+        ("pr_body", settings.bot_login, "PR body"),
+        ("comment", "can1357", "prior PR context"),
+    ]
     assert sandbox.ensure_calls[0]["number"] == 42
     assert sandbox.ensure_calls[0]["existing_branch"] == branch
     row = db.get_issue("octo/widget#42")