Preserve imported persona model on provider select

desktop/src/features/agents/ui/PersonaDialog.tsx

@@ -32,6 +32,7 @@ import {
   getImportErrorLabel,
   IMPORT_ERROR_VISIBILITY_MS,
 } from "./personaDialogImportState";
+import { shouldClearModelForRuntimeChange } from "./personaRuntimeModel";
 
 type PersonaDialogProps = {
   open: boolean;
@@ -543,8 +544,16 @@ export function PersonaDialog({
               <Select
                 disabled={isPending || runtimesLoading}
                 onValueChange={(nextRuntime) => {
+                  const previousRuntime = runtime;
                   setRuntime(nextRuntime);
-                  setModel("");
+                  if (
+                    shouldClearModelForRuntimeChange(
+                      previousRuntime,
+                      nextRuntime,
+                    )
+                  ) {
+                    setModel("");
+                  }
                 }}
                 value={runtime}
               >

desktop/src/features/agents/ui/personaRuntimeModel.test.mjs

@@ -0,0 +1,16 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { shouldClearModelForRuntimeChange } from "./personaRuntimeModel.ts";
+
+test("shouldClearModelForRuntimeChange preserves model for first runtime selection", () => {
+  assert.equal(shouldClearModelForRuntimeChange("", "goose"), false);
+});
+
+test("shouldClearModelForRuntimeChange clears model when switching runtimes", () => {
+  assert.equal(shouldClearModelForRuntimeChange("goose", "claude"), true);
+});
+
+test("shouldClearModelForRuntimeChange keeps model for unchanged runtime", () => {
+  assert.equal(shouldClearModelForRuntimeChange("goose", "goose"), false);
+});

desktop/src/features/agents/ui/personaRuntimeModel.ts

@@ -0,0 +1,9 @@
+export function shouldClearModelForRuntimeChange(
+  previousRuntime: string,
+  nextRuntime: string,
+): boolean {
+  const previous = previousRuntime.trim();
+  const next = nextRuntime.trim();
+
+  return previous.length > 0 && next.length > 0 && previous !== next;
+}