fix(web): re-selecting the current model keeps its options

apps/web/src/components/ChatView.tsx

@@ -119,6 +119,7 @@ import {
   applyClaudePromptEffortPrefix,
   createModelSelection,
   formatModelSlugName,
+  resolveModelPick,
   resolvePromptInjectedEffort,
   resolveSelectableModel,
 } from "@t3tools/shared/model";
@@ -10434,14 +10435,18 @@ export default function ChatView(props: ChatViewProps) {
       }
       // Restore this model's own remembered options; without any, start it
       // from its default rather than carrying the previous model's over.
-      const rememberedOptions =
+      const nextModelSelection = resolveModelPick(
+        composerRef.current?.getSendContext().selectedModelSelection,
+        instanceId,
+        resolvedModel,
         useComposerDraftStore.getState().stickyOptionsByModelByProvider[instanceId]?.[
           resolvedModel
-        ];
-      const nextModelSelection: ModelSelection =
-        rememberedOptions !== undefined && rememberedOptions.length > 0
-          ? { instanceId, model: resolvedModel, options: [...rememberedOptions] }
-          : { instanceId, model: resolvedModel };
+        ],
+      );
+      if (!nextModelSelection) {
+        if (options?.focusComposer !== false) scheduleComposerFocus();
+        return;
+      }
       const modelChangeBlockReason = getStartedThreadModelChangeBlockReason({
         providers: providerStatuses,
         hasStartedSession: activeRuntime !== null,
@@ -10472,6 +10477,7 @@ export default function ChatView(props: ChatViewProps) {
     [
       activeThread,
       activeRuntime,
+      composerRef,
       lockedProvider,
       supportsProviderSwitchingViaHandoff,
       scheduleComposerFocus,

apps/web/src/components/settings/ProjectDefaultsSettings.tsx

@@ -4,7 +4,7 @@ import {
   type ProviderInstanceId,
   type WorktreeSubmodules,
 } from "@t3tools/contracts";
-import { createModelSelection } from "@t3tools/shared/model";
+import { createModelSelection, resolveModelPick } from "@t3tools/shared/model";
 import { resolveProjectSettings } from "@t3tools/shared/projectSettings";
 import { useNavigate } from "@tanstack/react-router";
 
@@ -173,8 +173,10 @@ export function ProjectDefaultsSettings({ category }: { category: ProjectSetting
                     search: { environmentId: representative.environmentId, instanceId },
                   });
               }}
+              // Re-picking the current model still writes it, which pins an
+              // automatic default and unifies a mixed scope without losing traits.
               onInstanceModelChange={(instanceId, model) =>
-                setModel(createModelSelection(instanceId, model))
+                setModel(resolveModelPick(selection, instanceId, model) ?? selection)
               }
             />
             {!mixedModel ? (

apps/web/src/components/settings/SettingsPanels.tsx

@@ -47,7 +47,7 @@ import {
   SidebarProjectSortOrder,
 } from "@t3tools/contracts/settings";
 import { resolveServerBackgroundActivitySettings } from "@t3tools/shared/backgroundActivitySettings";
-import { createModelSelection } from "@t3tools/shared/model";
+import { createModelSelection, resolveModelPick } from "@t3tools/shared/model";
 import * as Duration from "effect/Duration";
 import * as Equal from "effect/Equal";
 import * as Schema from "effect/Schema";
@@ -3281,7 +3281,9 @@ export function GeneralSettingsPanel() {
                       textGenerationModelSelection: resolveAppModelSelectionState(
                         {
                           ...settings,
-                          textGenerationModelSelection: createModelSelection(instanceId, model),
+                          textGenerationModelSelection:
+                            resolveModelPick(textGenerationModelSelection, instanceId, model) ??
+                            textGenerationModelSelection,
                         },
                         textGenerationProviders,
                       ),

packages/shared/src/model.test.ts

@@ -14,6 +14,7 @@ import {
   getModelSelectionStringOptionValue,
   getProviderOptionDescriptors,
   readCustomModelEntries,
+  resolveModelPick,
   toCustomModelSetting,
   getProviderOptionBooleanSelectionValue,
   getProviderOptionStringSelectionValue,
@@ -224,6 +225,33 @@ describe("descriptor helpers", () => {
   });
 });
 
+describe("resolveModelPick", () => {
+  const claude = ProviderInstanceId.make("claudeAgent");
+  const current = createModelSelection(claude, "claude-opus-5-5", [
+    { id: "effort", value: "medium" },
+  ]);
+  const remembered = [{ id: "effort", value: "high" }];
+
+  it("changes nothing when the current model is picked again", () => {
+    expect(resolveModelPick(current, claude, "claude-opus-5-5", remembered)).toBeNull();
+  });
+
+  it("starts any other model from the given options", () => {
+    expect(resolveModelPick(current, claude, "claude-sonnet-5-5", remembered)).toEqual({
+      instanceId: "claudeAgent",
+      model: "claude-sonnet-5-5",
+      options: [{ id: "effort", value: "high" }],
+    });
+    expect(
+      resolveModelPick(current, ProviderInstanceId.make("claude_work"), "claude-opus-5-5"),
+    ).toEqual({ instanceId: "claude_work", model: "claude-opus-5-5" });
+    expect(resolveModelPick(null, claude, "claude-opus-5-5")).toEqual({
+      instanceId: "claudeAgent",
+      model: "claude-opus-5-5",
+    });
+  });
+});
+
 describe("applyClaudePromptEffortPrefix", () => {
   it("keeps slash commands intact when ultrathink is selected", () => {
     expect(applyClaudePromptEffortPrefix("/compact", "ultrathink")).toBe("/compact");

packages/shared/src/model.ts

@@ -484,6 +484,22 @@ export function createModelSelection(
   return selections.length > 0 ? { ...base, options: selections } : base;
 }
 
+/**
+ * The selection a model picker pick produces, starting the picked model from
+ * `options` (for example its remembered options). Returns null when the pick
+ * names the current instance and model, so confirming the model already in use
+ * keeps the options it runs with.
+ */
+export function resolveModelPick(
+  current: ModelSelection | null | undefined,
+  instanceId: ProviderInstanceId,
+  model: string,
+  options?: ReadonlyArray<ProviderOptionSelection> | null,
+): ModelSelection | null {
+  if (current?.instanceId === instanceId && current.model === model) return null;
+  return createModelSelection(instanceId, model, options);
+}
+
 /**
  * Returns the effort value if it is a prompt-injected value according to
  * any select descriptor in the given capabilities, or null otherwise.