feat: added PR fallback routing and followup comment context propagation

- Routed PR conversation and review-comment webhooks to `issue_key(repo, pr_number)` when origin mapping was missing.
- Added PR-origin context via `origin` in persona outputs for `followup_comment` and `directive`.
- Updated directive and follow-up prompt templates to use `origin.description` when origin issue is unavailable.

src/robomp/github_events.py

@@ -138,10 +138,10 @@ def route(
     """Decide whether and how to handle a webhook event.
 
     `resolve_issue_from_pr(repo, pr_number)` maps a PR number back to its
-    originating-issue key (e.g. `octo/widget#42`). User comments on PRs are
-    only actionable when that mapping exists, so they serialize on the same
-    inflight key as the issue's own events. PR lifecycle cleanup may still
-    fall back to a PR-scoped key when the origin row is gone.
+    originating-issue key (e.g. `octo/widget#42`). PR-derived events prefer
+    that key so follow-ups serialize with the original issue. If the mapping
+    is missing, the event is still actionable and falls back to the PR's own
+    issue key (`octo/widget#1080`).
     """
     repo = _repo_full_name(payload)
     if repo is None or repo.lower() not in allowlist:
@@ -154,12 +154,7 @@ def route(
             resolved = resolve_issue_from_pr(repo, pr_number)  # type: ignore[arg-type]
             if resolved:
                 return resolved
-        return f"{repo}#pr-{pr_number}"
-
-    def _resolve_origin_issue_key(pr_number: int) -> str | None:
-        if resolve_issue_from_pr is None:
-            return None
-        return resolve_issue_from_pr(repo, pr_number)  # type: ignore[arg-type]
+        return issue_key(repo, pr_number)  # type: ignore[arg-type]
 
     def _reviewer_bot_login(user: Mapping[str, Any] | None) -> str | None:
         """Return the lowercased login if this user is a configured reviewer bot."""
@@ -226,11 +221,11 @@ def route(
             return RouteDecision("skip", None, repo, None, "comment missing issue number")
         if "pull_request" in issue:
             # Conversation comment on a PR. The PR number lives at issue.number
-            # on this payload type. Only mapped bot PR follow-ups are
-            # actionable; unknown PRs must not consume per-user quota.
-            key = _resolve_origin_issue_key(number)
-            if key is None:
-                return RouteDecision("skip", None, repo, None, f"PR #{number} is not mapped to an issue")
+            # on this payload type. Prefer the originating issue key when the
+            # DB has it, but do not drop bot-authored follow-ups just because
+            # the PR mapping was lost; the worker can recover from the PR
+            # branch or handle the PR directly.
+            key = _resolve_pr_key(number)
             login, assoc = _submitter_info(comment)
             return RouteDecision(
                 "queue",
@@ -267,9 +262,7 @@ def route(
         number = pr.get("number")
         if not isinstance(number, int):
             return RouteDecision("skip", None, repo, None, "PR missing number")
-        key = _resolve_origin_issue_key(number)
-        if key is None:
-            return RouteDecision("skip", None, repo, None, f"PR #{number} is not mapped to an issue")
+        key = _resolve_pr_key(number)
         login, assoc = _submitter_info(comment)
         return RouteDecision(
             "queue",

src/robomp/persona.py

@@ -209,11 +209,17 @@ def _inbound_scope(issue: IssueInfo, pr_number: int | None) -> dict[str, Any]:
     `kind` field lets prompts say "PR" or "issue" without branching in the
     template engine.
     """
-    if pr_number is not None and pr_number != issue.number:
+    if pr_number is not None:
         return {"kind": "PR", "number": pr_number}
     return {"kind": "issue", "number": issue.number}
 
 
+def _origin_scope(issue: IssueInfo) -> dict[str, Any]:
+    if issue.is_pull_request:
+        return {"description": "originating issue unknown; handling this PR directly"}
+    return {"description": f"originating issue #{issue.number}"}
+
+
 def followup_comment(
     *,
     repo: RepoInfo,
@@ -232,6 +238,7 @@ def followup_comment(
             "comment": comment,
             "state": {"pr_status": pr_status},
             "inbound": _inbound_scope(issue, pr_number),
+            "origin": _origin_scope(issue),
         },
     )
 
@@ -258,6 +265,7 @@ def directive(
             "thread": _render_thread(getattr(directive, "thread", ()) or ()),
             "state": {"pr_status": pr_status},
             "inbound": _inbound_scope(issue, pr_number),
+            "origin": _origin_scope(issue),
         },
     )
 

src/robomp/prompts/directive.md

@@ -1,9 +1,9 @@
 # Directive on {{repo.full_name}}#{{inbound.number}} ({{inbound.kind}})
 
 **@{{directive.author}}** posted an authoritative directive on this
-{{inbound.kind}} thread (originating issue #{{issue.number}}). They're
-either a maintainer who tagged you (`@bot`) or a configured reviewer bot
-whose comments you treat as binding. Current PR state:
+{{inbound.kind}} thread ({{origin.description}}). They're either a maintainer
+who tagged you (`@bot`) or a configured reviewer bot whose comments you treat
+as binding. Current PR state:
 `{{state.pr_status}}`. The directive overrides any prior plan or seed
 todos.
 

src/robomp/prompts/followup_comment.md

@@ -1,7 +1,7 @@
 # Follow-up on {{repo.full_name}}#{{inbound.number}} ({{inbound.kind}})
 
-A new comment arrived on this {{inbound.kind}} thread (originating issue
-#{{issue.number}}). Current PR state: `{{state.pr_status}}`.
+A new comment arrived on this {{inbound.kind}} thread ({{origin.description}}).
+Current PR state: `{{state.pr_status}}`.
 
 ## New comment by @{{comment.author}} ({{comment.created_at}})
 

tests/test_github_events.py

@@ -167,8 +167,8 @@ def test_route_pr_conversation_uses_resolver_for_inflight_key() -> None:
     assert decision.issue_key == "octo/widget#42"
 
 
-def test_route_pr_conversation_skips_when_resolver_misses() -> None:
-    """Unknown PR comments are not actionable and must not count as submissions."""
+def test_route_pr_conversation_falls_back_to_pr_key_when_resolver_misses() -> None:
+    """Unmapped PR comments still queue so the worker can recover from the PR branch."""
 
     decision = route(
         "issue_comment",
@@ -182,10 +182,10 @@ def test_route_pr_conversation_skips_when_resolver_misses() -> None:
         bot_login=BOT,
         resolve_issue_from_pr=lambda _r, _n: None,
     )
-    assert not decision.should_queue
-    assert decision.submitter is None
-    assert decision.issue_key is None
-    assert "not mapped" in decision.reason
+    assert decision.should_queue
+    assert decision.task == "handle_pr_conversation"
+    assert decision.submitter == "alice"
+    assert decision.issue_key == "octo/widget#9"
 
 
 def test_route_review_only_for_bot_authored_pr() -> None:
@@ -219,7 +219,7 @@ def test_route_review_only_for_bot_authored_pr() -> None:
     assert not not_ours.should_queue
 
 
-def test_route_review_comment_skips_when_resolver_misses() -> None:
+def test_route_review_comment_falls_back_to_pr_key_when_resolver_misses() -> None:
     decision = route(
         "pull_request_review_comment",
         {
@@ -232,8 +232,10 @@ def test_route_review_comment_skips_when_resolver_misses() -> None:
         bot_login=BOT,
         resolve_issue_from_pr=lambda _r, _n: None,
     )
-    assert not decision.should_queue
-    assert decision.submitter is None
+    assert decision.should_queue
+    assert decision.task == "handle_review"
+    assert decision.submitter == "alice"
+    assert decision.issue_key == "octo/widget#9"
 
 
 def test_route_pr_closed_only_when_merged_by_bot() -> None:
@@ -262,7 +264,7 @@ def test_route_pr_closed_only_when_merged_by_bot() -> None:
     )
     assert fallback.should_queue
     assert fallback.task == "cleanup_workspace"
-    assert fallback.issue_key == "octo/widget#pr-9"
+    assert fallback.issue_key == "octo/widget#9"
     assert fallback.submitter is None
 
     payload["pull_request"]["merged"] = False  # type: ignore[index]

tests/test_server.py

@@ -773,20 +773,20 @@ def test_webhook_rate_limits_unknown_submitter_at_default_cap(rate_limited_setti
     assert states == ["queued", "queued", "skipped"]
 
 
-def test_webhook_unmapped_pr_comment_does_not_consume_submitter_budget(
+def test_webhook_unmapped_pr_comment_queues_with_pr_key_and_counts_budget(
     rate_limited_settings: Settings,
 ) -> None:
     app = create_app(rate_limited_settings)
     with TestClient(app) as client:
-        skipped = _post_pr_issue_comment(
+        queued = _post_pr_issue_comment(
             client,
             delivery="pr-unmapped",
             user="stranger",
             pr_number=900,
             association="NONE",
         )
-        assert skipped.status_code == 202
-        assert skipped.json()["state"] == "skipped"
+        assert queued.status_code == 202
+        assert queued.json()["state"] == "queued"
 
         states = []
         for i in range(3):
@@ -805,10 +805,9 @@ def test_webhook_unmapped_pr_comment_does_not_consume_submitter_budget(
     close_database()
 
     assert unmapped is not None
-    assert unmapped.issue_key is None
-    assert unmapped.last_error is not None
-    assert "not mapped" in unmapped.last_error
-    assert states == ["queued", "queued", "skipped"]
+    assert unmapped.issue_key == "octo/widget#900"
+    assert unmapped.last_error is None
+    assert states == ["queued", "skipped", "skipped"]
 
 
 def test_webhook_contributor_gets_higher_cap(rate_limited_settings: Settings) -> None:
@@ -1403,6 +1402,166 @@ def stub_run_task(monkeypatch: pytest.MonkeyPatch) -> list[dict]:
     return captured
 
 
+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
+
+    sandbox = _RecordingSandbox(tmp_path)
+    db = get_database(settings.sqlite_path)
+    repo = RepoInfo(
+        full_name="octo/widget", default_branch="main", clone_url="https://github.com/octo/widget.git", private=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,
+        html_url="https://github.com/octo/widget/pull/900",
+        head_ref="farm/abc12345/fix-flaky-parser",
+        base_ref="main",
+        state="open",
+        author=settings.bot_login,
+        head_repo="octo/widget",
+    )
+
+    async def _get_pull_request(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return pr_info
+
+    async def _get_repo(self, repo_full: str):
+        assert repo_full == "octo/widget"
+        return repo
+
+    async def _get_issue(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return pr_issue
+
+    monkeypatch.setattr(GitHubClient, "get_pull_request", _get_pull_request)
+    monkeypatch.setattr(GitHubClient, "get_repo", _get_repo)
+    monkeypatch.setattr(GitHubClient, "get_issue", _get_issue)
+
+    payload = {
+        "action": "created",
+        "issue": {"number": 900, "pull_request": {"url": "https://api.github.com/repos/octo/widget/pulls/900"}},
+        "comment": {"user": {"login": "can1357"}, "body": "please fix", "id": 10, "created_at": "2026-05-15T00:00:00Z"},
+        "repository": {"full_name": "octo/widget"},
+    }
+    await tasks.handle_pr_conversation(
+        settings=settings,
+        db=db,
+        github=GitHubClient("t"),
+        git_transport=LocalGitTransport(token=None),
+        sandbox=sandbox,
+        payload=payload,
+        delivery_id="test-pr-direct",
+    )
+
+    assert len(stub_run_task) == 1
+    call = stub_run_task[0]
+    assert call["task_kind"] == "handle_comment"
+    assert call["pr_number"] == 900
+    assert call["inputs"].issue.is_pull_request is True
+    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")
+    assert row is not None
+    assert row.pr_number == 900
+    assert row.branch == "farm/abc12345/fix-flaky-parser"
+    close_database()
+
+
+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
+
+    sandbox = _RecordingSandbox(tmp_path)
+    db = get_database(settings.sqlite_path)
+    branch = "farm/abc12345/fix-flaky-parser"
+    db.upsert_issue(key="octo/widget#42", repo="octo/widget", number=42, state="opened", branch=branch)
+    repo = RepoInfo(
+        full_name="octo/widget", default_branch="main", clone_url="https://github.com/octo/widget.git", private=False
+    )
+    issue = IssueInfo(
+        repo="octo/widget",
+        number=42,
+        title="Parser is flaky",
+        body="issue body",
+        state="open",
+        author="alice",
+        labels=(),
+        is_pull_request=False,
+    )
+    pr_info = PullRequestInfo(
+        repo="octo/widget",
+        number=900,
+        html_url="https://github.com/octo/widget/pull/900",
+        head_ref=branch,
+        base_ref="main",
+        state="open",
+        author=settings.bot_login,
+        head_repo="octo/widget",
+    )
+
+    async def _get_pull_request(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 900
+        return pr_info
+
+    async def _get_repo(self, repo_full: str):
+        assert repo_full == "octo/widget"
+        return repo
+
+    async def _get_issue(self, repo_full: str, number: int):
+        assert repo_full == "octo/widget"
+        assert number == 42
+        return issue
+
+    monkeypatch.setattr(GitHubClient, "get_pull_request", _get_pull_request)
+    monkeypatch.setattr(GitHubClient, "get_repo", _get_repo)
+    monkeypatch.setattr(GitHubClient, "get_issue", _get_issue)
+
+    payload = {
+        "action": "created",
+        "issue": {"number": 900, "pull_request": {"url": "https://api.github.com/repos/octo/widget/pulls/900"}},
+        "comment": {"user": {"login": "can1357"}, "body": "please fix", "id": 11, "created_at": "2026-05-15T00:00:00Z"},
+        "repository": {"full_name": "octo/widget"},
+    }
+    await tasks.handle_pr_conversation(
+        settings=settings,
+        db=db,
+        github=GitHubClient("t"),
+        git_transport=LocalGitTransport(token=None),
+        sandbox=sandbox,
+        payload=payload,
+        delivery_id="test-pr-repair",
+    )
+
+    assert len(stub_run_task) == 1
+    call = stub_run_task[0]
+    assert call["inputs"].issue.number == 42
+    assert call["pr_number"] == 900
+    assert sandbox.ensure_calls[0]["number"] == 42
+    assert sandbox.ensure_calls[0]["existing_branch"] == branch
+    row = db.get_issue("octo/widget#42")
+    assert row is not None
+    assert row.pr_number == 900
+    close_database()
+
+
 async def test_handle_comment_directive_bootstraps_untriaged_issue(
     settings: Settings, tmp_path: Path, stub_run_task, monkeypatch
 ) -> None: