fix(link): revoke endpoint was disabled by its own rate-limit rule

Live QA: every call to /v1/devices/revoke returned 429 retry_after=3600.
The rule was written (0, 3600) with a comment saying 'never throttle someone
out of signing a lost laptop out' -- but in this limiter a limit of 0
DISABLES the endpoint outright. The comment said unlimited; the code said
never. Set to 600/hour instead.

Every unit test passed while the endpoint was 100% dead over HTTP, because
they called svc.revoke_device() directly and never went through the handler.
Added 4 tests that speak HTTP, including one that fails if ANY route in
DEFAULT_RATE_RULES is configured to 0.

176 tests (was 172).

tests/test_server.py

@@ -728,6 +728,62 @@ class TestTokenNameUniqueness(ServiceTestBase):
         self.assertIsNone(self.svc.whoami(a["token"]))
         self.assertEqual(self.svc.whoami(b["token"]), "alice")
 
+
+class TestDeviceEndpointsOverHttp(HandlerTestBase):
+    """Through the real handler, not the service method.
+
+    The first live run of the revoke endpoint returned 429 on every call
+    while every unit test passed: the tests called svc.revoke_device()
+    directly, so nothing ever went through the rate limiter. Any route whose
+    limit is a policy decision needs at least one test that speaks HTTP.
+    """
+
+    def setUp(self):
+        super().setUp()
+        self.enable_test_mode()
+        self.a = self.stub_link("s1", "alice", device="laptop",
+                                device_id="dev-a")[1]
+        self.b = self.stub_link("s1", "alice", device="desktop",
+                                device_id="dev-b")[1]
+
+    def post(self, path, obj):
+        body = json.dumps(obj).encode()
+        return self.raw_post(path, body,
+                             {"Content-Type": "application/json",
+                              "Content-Length": str(len(body))})
+
+    def test_revoke_is_reachable_and_not_rate_limited_away(self):
+        status, resp = self.post("/v1/devices/revoke",
+                                 {"token": self.b["token"],
+                                  "device_id": "dev-a"})
+        self.assertEqual(status, 200, resp)
+        self.assertIsNone(self.svc.whoami(self.a["token"]))
+
+    def test_repeated_revokes_keep_working(self):
+        """A person signing several lost machines out in one sitting must not
+        be locked out partway through."""
+        for i in range(12):
+            self.stub_link("s1", "alice", device=f"d{i}", device_id=f"gone-{i}")
+        for i in range(12):
+            status, resp = self.post("/v1/devices/revoke",
+                                     {"token": self.b["token"],
+                                      "device_id": f"gone-{i}"})
+            self.assertEqual(status, 200, f"revoke {i}: {resp}")
+
+    def test_devices_and_audit_are_reachable_over_http(self):
+        status, resp = self.post("/v1/devices", {"token": self.a["token"]})
+        self.assertEqual(status, 200)
+        self.assertEqual(len(resp["devices"]), 2)
+        status, resp = self.post("/v1/audit", {"token": self.a["token"]})
+        self.assertEqual(status, 200)
+        self.assertTrue(resp["events"])
+
+    def test_no_route_a_client_uses_is_configured_to_zero(self):
+        """0 means DISABLED in this limiter, so a zero on a live route is a
+        dead endpoint, not an unlimited one."""
+        for route, (limit, _window) in granthi_link.DEFAULT_RATE_RULES.items():
+            self.assertGreater(limit, 0, f"{route} is disabled by its rule")
+
 if __name__ == "__main__":
     unittest.main()