fix(agents): prioritize per-model thinking defaults (#30439)

* fix(agents): honor per-model thinking defaults

* fix(agents): preserve thinking fallback with model defaults

---------

Co-authored-by: Mark L <73659136+markliuyuxiang@users.noreply.github.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/commands/agent.test.ts

@@ -734,6 +734,25 @@ describe("agentCommand", () => {
     });
   });
 
+  it("prefers per-model thinking over global thinkingDefault", async () => {
+    await withTempHome(async (home) => {
+      const store = path.join(home, "sessions.json");
+      mockConfig(home, store, {
+        thinkingDefault: "low",
+        models: {
+          "anthropic/claude-opus-4-5": {
+            params: { thinking: "high" },
+          },
+        },
+      });
+
+      await agentCommand({ message: "hi", to: "+1555" }, runtime);
+
+      const callArgs = vi.mocked(runEmbeddedPiAgent).mock.calls.at(-1)?.[0];
+      expect(callArgs?.thinkLevel).toBe("high");
+    });
+  });
+
   it("prints JSON payload when requested", async () => {
     await withTempHome(async (home) => {
       vi.mocked(runEmbeddedPiAgent).mockResolvedValue({

src/commands/agent.ts

@@ -588,11 +588,7 @@ export async function agentCommand(
       });
     }
 
-    let resolvedThinkLevel =
-      thinkOnce ??
-      thinkOverride ??
-      persistedThinking ??
-      (agentCfg?.thinkingDefault as ThinkLevel | undefined);
+    let resolvedThinkLevel = thinkOnce ?? thinkOverride ?? persistedThinking;
     const resolvedVerboseLevel =
       verboseOverride ?? persistedVerbose ?? (agentCfg?.verboseDefault as VerboseLevel | undefined);