fix(webhook): label re-read must hit /api/v1, not the bare host

GITEA_API is the host with no version prefix — ai_review._get / _post append
/api/v1 per call. The re-read helper didn't, so it 404'd on every review and
silently fell back to the payload's verdict: "could not re-read labels for
gitea_admin/pragent#10: HTTP Error 404" in the pod log, usage block still
missing. Caught by labelling PR #10 AI-REVIEW then AI-USAGE, which is the
exact sequence the fix exists to handle.

Test asserts the composed URL, since a wrong path here fails silently by
design (the helper swallows errors so a review is never lost over a usage
section).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B11e8TZZxJyzHW7jj7KWUN

pilot/webhook_server.py

@@ -186,7 +186,9 @@ def _fetch_current_labels(repo: str, index: str) -> list:
     opt-in is lost — the review posts without its usage block. Reading the
     labels again at review start closes that window.
     """
-    url = f"{GITEA_API}/repos/{repo}/issues/{index}/labels"
+    # GITEA_API is the bare host (no /api/v1) — every caller appends the
+    # version prefix itself; see ai_review._get / _post.
+    url = f"{GITEA_API}/api/v1/repos/{repo}/issues/{index}/labels"
     req = urllib.request.Request(url, headers={
         "Authorization": f"token {BOT_TOKEN}",
         "Accept": "application/json",

tests/pilot/test_webhook_server.py

@@ -162,6 +162,27 @@ def test_run_review_keeps_usage_off_when_label_absent(monkeypatch):
     assert seen["report_usage"] is False
 
 
+def test_fetch_current_labels_hits_the_versioned_api_path(monkeypatch):
+    # GITEA_API is the bare host; the /api/v1 prefix is the caller's job.
+    # Getting this wrong 404s silently and the opt-in is lost — which is
+    # exactly what shipped the first time.
+    seen = {}
+
+    class _Resp:
+        def read(self): return b'[{"name": "AI-USAGE"}]'
+        def __enter__(self): return self
+        def __exit__(self, *a): return False
+
+    def _urlopen(req, timeout=None):
+        seen["url"] = req.full_url
+        return _Resp()
+
+    monkeypatch.setattr(ws.urllib.request, "urlopen", _urlopen)
+    out = ws._fetch_current_labels("o/r", "9")
+    assert out == [{"name": "AI-USAGE"}]
+    assert seen["url"] == f"{ws.GITEA_API}/api/v1/repos/o/r/issues/9/labels"
+
+
 def test_label_reread_failure_is_not_fatal(monkeypatch):
     # A dead API must not take the review down with it — the re-read is a
     # best-effort upgrade of an opt-in flag, nothing more.