test: skip stale notification chatd flakes (#25376)

These chatd tests are flaking for the same stale control-notification
race tracked by CODAGT-353, so this change skips the newly reflaking
advisor-chain and `TestPatchChatMessage/ChangesModel` tests and rewrites
the older `TODO(hugodutka)` skips to point at the same root cause. This
keeps the known flakes documented consistently until the chatd
notification-flow refactor lands.

Closes CODAGT-427
Closes https://github.com/coder/internal/issues/1510

coderd/exp_chats_test.go

@@ -7761,6 +7761,14 @@ func TestPatchChatMessage(t *testing.T) {
 
 	t.Run("ChangesModel", func(t *testing.T) {
 		t.Parallel()
+		// TODO(CODAGT-353): Re-enable this test after the chatd notification flow
+		// refactor gives workers enough causal information to distinguish stale
+		// control NOTIFY messages from real interrupts. The current design reuses
+		// the same status notification shape for wake-only and interrupt intents,
+		// so a stale NOTIFY can cancel a new processChat run. This subtest hits the
+		// same root cause via the persistInterruptedStep ownership gate, where a
+		// late insert from the previous turn regresses chats.last_model_config_id.
+		t.Skip("skipped until chatd notification flow refactor handles stale control notifications")
 
 		ctx := testutil.Context(t, testutil.WaitLong)
 		client := newChatClient(t)

coderd/x/chatd/chatd_test.go

@@ -1100,8 +1100,12 @@ func TestRootExploreChatExcludesWebSearchProviderToolAtRuntime(t *testing.T) {
 
 func TestExploreChatSendMessageCannotMutateMCPSnapshot(t *testing.T) {
 	t.Parallel()
-	// TODO(hugodutka): Unskip when chatd is free of race conditions.
-	t.Skip("skipped due to inherent race condition; see https://github.com/coder/internal/issues/1493")
+	// TODO(CODAGT-353): Re-enable this test after the chatd notification flow
+	// refactor gives workers enough causal information to distinguish stale
+	// control NOTIFY messages from real interrupts. The current design reuses
+	// the same status notification shape for wake-only and interrupt intents,
+	// so a stale NOTIFY can cancel a new processChat run.
+	t.Skip("skipped until chatd notification flow refactor handles stale control notifications")
 
 	db, ps := dbtestutil.NewDB(t)
 	ctx := testutil.Context(t, testutil.WaitLong)
@@ -10104,6 +10108,12 @@ func TestAdvisorGating_ExploreSubagent(t *testing.T) {
 // message, losing the context the outer model had been building on.
 func TestAdvisorChainMode_SnapshotKeepsFullHistory(t *testing.T) {
 	t.Parallel()
+	// TODO(CODAGT-353): Re-enable this test after the chatd notification flow
+	// refactor gives workers enough causal information to distinguish stale
+	// control NOTIFY messages from real interrupts. The current design reuses
+	// the same status notification shape for wake-only and interrupt intents,
+	// so a stale NOTIFY can cancel a new processChat run.
+	t.Skip("skipped until chatd notification flow refactor handles stale control notifications")
 
 	db, ps := dbtestutil.NewDB(t)
 	ctx := testutil.Context(t, testutil.WaitLong)

enterprise/coderd/x/chatd/chatd_test.go

@@ -1426,8 +1426,12 @@ func TestSubscribeRelayDialCanceledOnFastCompletion(t *testing.T) {
 // condition where the relay is too slow.
 func TestSubscribeRelayEstablishedMidStream(t *testing.T) {
 	t.Parallel()
-	// TODO(hugodutka): Unskip when chatd is free of race conditions.
-	t.Skip("skipped due to inherent race condition; see https://github.com/coder/internal/issues/1455")
+	// TODO(CODAGT-353): Re-enable this test after the chatd notification flow
+	// refactor gives workers enough causal information to distinguish stale
+	// control NOTIFY messages from real interrupts. The current design reuses
+	// the same status notification shape for wake-only and interrupt intents,
+	// so a stale NOTIFY can cancel a new processChat run.
+	t.Skip("skipped until chatd notification flow refactor handles stale control notifications")
 
 	db, ps := dbtestutil.NewDB(t)
 	workerID := uuid.New()