test: avoid unread body in Windows auth guard probe

docs/evidence/main-windows-denied-post-2026-10-28.md

@@ -0,0 +1,18 @@
+# Main Windows test gate, 28 October 2026
+
+Exact main commit `b5bbcec1a0cc3f8b3d25ef2686fd8315e209f167`
+([checks run 40723931638](https://github.com/saphid/frame-control/actions/runs/40723931638))
+failed in `server-tests (windows-latest, 3.12)`. Its server test step had one
+error: `test_settings_need_and_accept_the_ui_key` received Windows
+`ConnectionAbortedError [WinError 10053]` while reading an unauthorized
+POST response. The test sent a JSON body, but the missing-key guard rejects
+the request before reading it. Closing a connection with an unread body can
+reset it on Windows; that is the likely cause, rather than a settings write
+failure. The other Windows tests completed, and the exact-main native Decky
+runtime run passed.
+
+The test now sends an empty POST when checking that a missing key is refused.
+Its subsequent authorized POST still sends a settings body and verifies the
+saved value. The local `tests/test_server.py` module passed 45 tests after
+this change. Hosted Windows CI on the repair commit and green exact-main CI
+remain required before further merges.

tests/test_server.py

@@ -497,7 +497,10 @@ class ArtworkSettings(unittest.TestCase):
                         time.sleep(0.05)
                 key = {"X-Frame-UI": "1", "Content-Type": "application/json"}
                 self.assertEqual(request("GET", "/api/settings/artwork")[0], 403)
-                self.assertEqual(request("POST", "/api/settings/artwork", {"steamgriddb_api_key": "abc"})[0], 403)
+                # The missing-key guard runs before reading a body. Leaving an
+                # unread body on Windows can reset this test connection before
+                # http.client receives the 403 response.
+                self.assertEqual(request("POST", "/api/settings/artwork")[0], 403)
                 status, payload = request("GET", "/api/settings/artwork", headers=key)
                 self.assertEqual((status, json.loads(payload)["steamgriddb_configured"]), (200, False))
                 status, payload = request("POST", "/api/settings/artwork", {"steamgriddb_api_key": "abc_1"}, key)