Update Harbor client and gateway integration workflows

test/web/harbor-state.test.js

@@ -56,6 +56,10 @@ test('typed Harbor client validates unknown state and isolates wire compatibilit
     gatewayAvailable: true,
   });
   assert.equal(Object.hasOwn(parsed, 'proxyPort'), false);
+  assert.throws(() => parseHarborState({
+    ...snapshot,
+    failover: { ...snapshot.failover, policy: { ...snapshot.failover.policy, intervalMs: 'fast' } },
+  }), { code: 'INCOMPATIBLE_API' });
   let incompatible;
   try {
     parseHarborState({ ...snapshot, revision: -1 });
@@ -116,6 +120,21 @@ test('an equal revision keeps the current snapshot identity', () => {
   assert.equal(next.snapshot.selection.desiredServerId, 'one');
 });
 
+test('equal revision accepts only newer failover observations and retires old epochs', () => {
+  const value = (epoch, sequence, status) => ({
+    ...snapshot(4, 'one'),
+    failover: { observationEpoch: epoch, observationSequence: sequence, status },
+  });
+  let state = receive(initialHarborState, value('epoch-a', 1, 'primary'));
+  state = receive(state, value('epoch-a', 2, 'waiting-for-idle'));
+  assert.equal(state.snapshot.failover.status, 'waiting-for-idle');
+  state = receive(state, value('epoch-b', 1, 'reserve'));
+  assert.equal(state.snapshot.failover.status, 'reserve');
+  state = receive(state, value('epoch-a', 99, 'primary'));
+  assert.equal(state.snapshot.failover.status, 'reserve');
+  assert.deepEqual(state.failoverTransport.retiredEpochs, ['epoch-a']);
+});
+
 test('selection has no client-side shadow and follows canonical profile snapshots', () => {
   const state = receive(initialHarborState, snapshot(2, 'two'));
   assert.equal(Object.hasOwn(state, 'pendingServerId'), false);