feat(webhook): pull reject reason from latest comment

handle_verdict(rejected): the reason is now pulled from the issue latest Plane
comment (_latest_comment_reason: GET comments, newest by created_at, HTML
stripped) instead of a fixed stub. Slava writes the reason in a comment before
flipping the status to Rejected. Falls back to a fixed note when there is no
comment / the API call fails.

tests: add test_status_only_verdict.py (test_inreview_comment_does_not_revert
[bug 3 root], test_any_comment_no_pipeline_action,
test_approved_status_advances_without_inprogress_reset,
test_rejected_status_pulls_reason_from_comment) and
test_inprogress_from_needs_input_relaunches_analyst in test_status_trigger.py.
Rewrote the comment-based tests (test_verdict_status, test_plane_approved/
rejected in test_webhooks) under the status-only model: comments are no-ops,
verdicts come from status changes.

src/webhooks/plane.py

@@ -252,7 +252,9 @@ async def handle_verdict(data: dict, project_id: str, approved: bool):
     the status to In Progress first, which made the board flicker In Progress
     before the next stage (part of bug 3); it is removed.
 
-    Rejected status -> rollback to the previous stage.
+    Rejected status -> rollback to the previous stage. The reason is pulled from
+    the issue's latest comment (Slava writes the reason in a comment before/with
+    flipping the status to Rejected).
     """
     plane_id = str(data.get("id") or "")
     task = get_task_by_plane_id(plane_id)
@@ -273,14 +275,62 @@ async def handle_verdict(data: dict, project_id: str, approved: bool):
         await _try_advance_stage(task_id, current_stage, repo, work_item_id, branch)
         return
 
-    # Rejected: roll back to the previous stage (reason note placeholder; the
-    # reason-from-comment lookup is added in a follow-up commit).
-    reason = "(rejected via status, see latest comment)"
+    # Rejected: pull the rejection reason from the issue's latest comment.
+    issue_id = task.get("plane_issue_id") or task.get("plane_id") or plane_id
+    reason = _latest_comment_reason(issue_id, repo, project_id)
     await _rollback_stage(
         task_id, current_stage, repo, work_item_id, branch, reason
     )
 
 
+def _latest_comment_reason(issue_id: str, repo: str, project_id: str = "") -> str:
+    """Fetch the issue's most recent comment text (HTML stripped) as the reject
+    reason. Slava writes the reason in a comment before/with flipping the status
+    to Rejected.
+
+    Returns a fixed fallback when there is no comment / the API call fails.
+    """
+    from ..plane_sync import (
+        PLANE_BASE,
+        PLANE_HEADERS,
+        WORKSPACE,
+        PROJECT_ID as _DEFAULT_PROJECT_ID,
+    )
+    fallback = "Rejected via status, no reason comment"
+    if not issue_id:
+        return fallback
+    _proj = get_project_by_repo(repo)
+    pid = _proj.plane_project_id if _proj else (project_id or _DEFAULT_PROJECT_ID)
+    url = (
+        f"{PLANE_BASE}/workspaces/{WORKSPACE}/projects/{pid}/issues/"
+        f"{issue_id}/comments/"
+    )
+    try:
+        resp = httpx.get(url, headers=PLANE_HEADERS, timeout=10)
+        if resp.status_code != 200:
+            logger.warning(
+                f"reject-reason: GET comments for {issue_id} returned "
+                f"{resp.status_code}"
+            )
+            return fallback
+        payload = resp.json()
+        comments = payload.get("results", payload) if isinstance(payload, dict) else payload
+        if not comments:
+            return fallback
+        latest = max(comments, key=lambda c: c.get("created_at", "") or "")
+        raw = (
+            latest.get("comment_stripped")
+            or latest.get("comment_html")
+            or latest.get("comment")
+            or ""
+        )
+        text = re.sub(r"<[^>]+>", "", raw).strip()
+        return text[:300] if text else fallback
+    except Exception as e:
+        logger.error(f"reject-reason: failed to fetch comments for {issue_id}: {e}")
+        return fallback
+
+
 async def handle_work_item_created(data: dict, project_id: str = ""):
     """Feature 1: creation does NOT start the pipeline anymore.