fix(server): changing Claude effort no longer re-sends the model

apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.test.ts

@@ -2621,6 +2621,7 @@ describe("ClaudeAdapterV2 background wake turns", () => {
     readonly close?: (sdkMessages: Queue.Queue<SDKMessage>) => Effect.Effect<void>;
     readonly interrupt?: Effect.Effect<void>;
     readonly setPermissionMode?: ClaudeAdapterV2.ClaudeAgentSdkQuerySession["setPermissionMode"];
+    readonly applyFlagSettings?: ClaudeAdapterV2.ClaudeAgentSdkQuerySession["applyFlagSettings"];
     readonly stopTask?: (
       taskId: string,
     ) => Effect.Effect<void, ClaudeAdapterV2.ClaudeAgentSdkQueryRunnerError>;
@@ -2768,7 +2769,9 @@ describe("ClaudeAdapterV2 background wake turns", () => {
                 applyFlagSettings: (settings) =>
                   Effect.sync(() => {
                     liveSelectionChanges.push(settings);
-                  }),
+                  }).pipe(
+                    Effect.andThen(() => options?.applyFlagSettings?.(settings) ?? Effect.void),
+                  ),
                 setPermissionMode: (mode) =>
                   Effect.sync(() => {
                     permissionModeChanges.push(mode);
@@ -4267,7 +4270,6 @@ describe("ClaudeAdapterV2 background wake turns", () => {
           yield* harness.runtime.startTurn(turn(4, { ...normal, model: "claude-sonnet-4-6" }));
           yield* settle;
           assert.deepEqual(harness.liveSelectionChanges, [
-            { model: "claude-opus-5-5" },
             { effortLevel: "xhigh", fastMode: true, ultracode: true },
             { model: "claude-sonnet-4-6" },
             { effortLevel: "high", fastMode: null, ultracode: null },
@@ -4292,7 +4294,7 @@ describe("ClaudeAdapterV2 background wake turns", () => {
           }
           assert.strictEqual(harness.getOpenedOptions(), originalOptions);
           assert.lengthOf(harness.offeredMessages, 4);
-          assert.lengthOf(harness.liveSelectionChanges, 4);
+          assert.lengthOf(harness.liveSelectionChanges, 3);
           assert.isTrue(yield* harness.hasPendingBackgroundWork);
         }).pipe(
           Effect.provide(
@@ -4302,6 +4304,64 @@ describe("ClaudeAdapterV2 background wake turns", () => {
       ),
   );
 
+  it.effect("re-sends the model on the turn after a live selection change fails", () =>
+    Effect.scoped(
+      Effect.gen(function* () {
+        let failFlags = true;
+        const harness = yield* makeWakeHarnessWithOptions({
+          applyFlagSettings: () =>
+            Effect.suspend(() => {
+              if (!failFlags) return Effect.void;
+              failFlags = false;
+              return Effect.fail(
+                new ClaudeAdapterV2.ClaudeAgentSdkQueryRunnerError({
+                  method: "applyFlagSettings",
+                  cause: new Error("control request failed"),
+                }),
+              );
+            }),
+        });
+        const now = yield* DateTime.now;
+        const opus = {
+          instanceId: ClaudeAdapterV2.CLAUDE_DEFAULT_INSTANCE_ID,
+          model: "claude-opus-5-5",
+        } satisfies ModelSelection;
+        const turn = (ordinal: number, modelSelection: ModelSelection) =>
+          makeClaudeTestTurnInput({
+            threadId: harness.threadId,
+            providerThread: harness.providerThread,
+            now,
+            attemptId: RunAttemptId.make(`attempt-failed-live-change:${ordinal}`),
+            text: `Request ${ordinal}`,
+            attachments: [],
+            providerTurnOrdinal: ordinal,
+            modelSelection,
+          });
+        yield* harness.runtime.startTurn(turn(1, opus));
+        yield* harness.offerAndWait(turnOneResult);
+        yield* Queue.take(harness.terminalReceipts);
+
+        const failed = yield* harness.runtime
+          .startTurn(turn(2, { ...opus, model: "claude-sonnet-4-6" }))
+          .pipe(Effect.result);
+        assert.equal(failed._tag, "Failure");
+
+        // The process may now run Sonnet, so returning to Opus must send it.
+        yield* harness.runtime.startTurn(turn(3, opus));
+        assert.deepEqual(harness.liveSelectionChanges, [
+          { model: "claude-sonnet-4-6" },
+          { effortLevel: "high", fastMode: null, ultracode: null },
+          { model: "claude-opus-5-5" },
+          { effortLevel: "medium", fastMode: false, ultracode: null },
+        ]);
+      }).pipe(
+        Effect.provide(
+          Layer.mergeAll(IdAllocator.layer, McpProviderSessions.layer, NodeServices.layer),
+        ),
+      ),
+    ),
+  );
+
   it.effect.each(["completed", "interrupted"] as const)(
     "projects Claude thinking blocks when %s",
     (status) =>

apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.ts

@@ -9659,7 +9659,13 @@ export const makeClaudeAdapterV2 = Effect.fn("makeClaudeAdapterV2")(function* (
               existing.openedPermissionMode === queryPolicy.permissionMode)
           ) {
             const live = existing;
-            yield* live.query.setModel(compiledSelection.apiModelId).pipe(
+            // Preserve launcher-selected models unless the model changed or a failed update left it unknown.
+            yield* (
+              live.selection.queryIdentity === "" ||
+              live.selection.apiModelId !== compiledSelection.apiModelId
+                ? live.query.setModel(compiledSelection.apiModelId)
+                : Effect.void
+            ).pipe(
               Effect.andThen(
                 live.query.applyFlagSettings(claudeLiveSelectionFlagSettings(compiledSelection)),
               ),