feat(KB-184): add model presets for task creation

- Add model preset types and settings fields with API validation
- Create model preset utility helpers for size-based auto-selection
- Add settings UI for managing model presets (create, edit, delete)
- Integrate preset selection into NewTaskModal with custom override option
- Add inline preset selection to InlineCreateCard component
- Persist modelPresetId in task store and preserve through archive/unarchive
- Add changeset and update AGENTS.md with feature documentation

packages/dashboard/app/components/__tests__/InlineCreateCard.test.tsx

@@ -3,7 +3,7 @@ import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render, screen, fireEvent, waitFor } from "@testing-library/react";
 import { InlineCreateCard } from "../InlineCreateCard";
 import type { Task, Column } from "@kb/core";
-import { fetchModels } from "../../api";
+import { fetchModels, fetchSettings } from "../../api";
 import type { ModelInfo } from "../../api";
 
 // Mock lucide-react
@@ -16,11 +16,17 @@ vi.mock("lucide-react", () => ({
   Terminal: () => null,
   Lightbulb: () => null,
   ListTree: () => null,
+  Zap: () => null,
 }));
 
 // Mock the api module
 vi.mock("../../api", () => ({
   fetchModels: vi.fn().mockResolvedValue([]),
+  fetchSettings: vi.fn().mockResolvedValue({
+    modelPresets: [],
+    autoSelectModelPreset: false,
+    defaultPresetBySize: {},
+  }),
   uploadAttachment: vi.fn(),
 }));
 
@@ -85,6 +91,11 @@ function chooseModel(label: "Executor Model" | "Validator Model", optionText: st
 beforeEach(() => {
   vi.clearAllMocks();
   vi.mocked(fetchModels).mockResolvedValue(MOCK_MODELS);
+  vi.mocked(fetchSettings).mockResolvedValue({
+    modelPresets: [],
+    autoSelectModelPreset: false,
+    defaultPresetBySize: {},
+  });
 });
 
 describe("InlineCreateCard blur-to-cancel", () => {
@@ -266,6 +277,48 @@ describe("InlineCreateCard model selector", () => {
     expect(props.onCancel).not.toHaveBeenCalled();
   });
 
+  it("does NOT call onCancel when focus leaves while the preset dropdown is open", () => {
+    vi.mocked(fetchSettings).mockResolvedValueOnce({
+      modelPresets: [{ id: "budget", name: "Budget", executorProvider: "anthropic", executorModelId: "claude-sonnet-4-5" }],
+      autoSelectModelPreset: false,
+      defaultPresetBySize: {},
+    });
+    const { props } = renderCard();
+    const textarea = screen.getByPlaceholderText("What needs to be done?");
+
+    fireEvent.click(screen.getByRole("button", { name: /Preset/i }));
+    textarea.focus();
+    fireEvent.focusOut(textarea, { relatedTarget: null });
+
+    expect(props.onCancel).not.toHaveBeenCalled();
+  });
+
+  it("includes selected preset id in the submit payload", async () => {
+    vi.mocked(fetchSettings).mockResolvedValueOnce({
+      modelPresets: [{ id: "budget", name: "Budget", executorProvider: "anthropic", executorModelId: "claude-sonnet-4-5", validatorProvider: "openai", validatorModelId: "gpt-4o" }],
+      autoSelectModelPreset: false,
+      defaultPresetBySize: {},
+    });
+    const { props } = renderCard();
+    const textarea = screen.getByPlaceholderText("What needs to be done?");
+
+    fireEvent.change(textarea, { target: { value: "Task with preset" } });
+    fireEvent.click(screen.getByRole("button", { name: /Preset/i }));
+    fireEvent.click(screen.getByRole("button", { name: "Budget" }));
+    fireEvent.click(screen.getByRole("button", { name: /Save/i }));
+
+    await waitFor(() => {
+      expect(props.onSubmit).toHaveBeenCalledWith(expect.objectContaining({
+        description: "Task with preset",
+        modelPresetId: "budget",
+        modelProvider: "anthropic",
+        modelId: "claude-sonnet-4-5",
+        validatorModelProvider: "openai",
+        validatorModelId: "gpt-4o",
+      }));
+    });
+  });
+
   it("does NOT call onCancel after a model override is selected and focus leaves the card", () => {
     const { props } = renderCard();
     const textarea = screen.getByPlaceholderText("What needs to be done?");

packages/dashboard/app/components/__tests__/NewTaskModal.test.tsx

@@ -2,6 +2,7 @@ import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render, screen, fireEvent, waitFor } from "@testing-library/react";
 import { NewTaskModal } from "../NewTaskModal";
 import type { Task, Column } from "@kb/core";
+import { fetchSettings } from "../../api";
 
 // Mock the api module
 vi.mock("../../api", () => ({
@@ -10,7 +11,11 @@ vi.mock("../../api", () => ({
     { provider: "anthropic", id: "claude-sonnet-4-5", name: "Claude Sonnet 4.5", reasoning: true, contextWindow: 200000 },
     { provider: "openai", id: "gpt-4o", name: "GPT-4o", reasoning: false, contextWindow: 128000 },
   ]),
-  updateTask: vi.fn().mockResolvedValue({}),
+  fetchSettings: vi.fn().mockResolvedValue({
+    modelPresets: [],
+    autoSelectModelPreset: false,
+    defaultPresetBySize: {},
+  }),
 }));
 
 function makeTask(id: string): Task {
@@ -196,6 +201,67 @@ describe("NewTaskModal", () => {
     });
   });
 
+  it("creates task with selected preset id and resolved models", async () => {
+    (fetchSettings as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      modelPresets: [
+        {
+          id: "budget",
+          name: "Budget",
+          executorProvider: "openai",
+          executorModelId: "gpt-4o",
+          validatorProvider: "anthropic",
+          validatorModelId: "claude-sonnet-4-5",
+        },
+      ],
+      autoSelectModelPreset: false,
+      defaultPresetBySize: {},
+    });
+
+    const { props } = renderNewTaskModal();
+    fireEvent.change(screen.getByLabelText(/Description/i), { target: { value: "Preset task" } });
+
+    await waitFor(() => expect(screen.getByLabelText("Preset")).toBeTruthy());
+    fireEvent.change(screen.getByLabelText("Preset"), { target: { value: "budget" } });
+    fireEvent.click(screen.getByRole("button", { name: "Create Task" }));
+
+    await waitFor(() => {
+      expect(props.onCreateTask).toHaveBeenCalledWith(expect.objectContaining({
+        description: "Preset task",
+        modelPresetId: "budget",
+        modelProvider: "openai",
+        modelId: "gpt-4o",
+        validatorModelProvider: "anthropic",
+        validatorModelId: "claude-sonnet-4-5",
+      }));
+    });
+  });
+
+  it("allows overriding a selected preset with custom models", async () => {
+    (fetchSettings as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      modelPresets: [
+        {
+          id: "budget",
+          name: "Budget",
+          executorProvider: "openai",
+          executorModelId: "gpt-4o",
+        },
+      ],
+      autoSelectModelPreset: false,
+      defaultPresetBySize: {},
+    });
+
+    renderNewTaskModal();
+    await waitFor(() => expect(screen.getByLabelText("Preset")).toBeTruthy());
+    fireEvent.change(screen.getByLabelText("Preset"), { target: { value: "budget" } });
+    expect(screen.getByText("Using preset: Budget")).toBeTruthy();
+
+    fireEvent.click(screen.getByRole("button", { name: "Override" }));
+    expect(screen.queryByText("Using preset: Budget")).toBeNull();
+
+    fireEvent.change(screen.getByLabelText("Preset"), { target: { value: "custom" } });
+    expect((screen.getByLabelText("Preset") as HTMLSelectElement).value).toBe("custom");
+  });
+
   it("toggles planning mode checkbox", () => {
     renderNewTaskModal();
     

packages/dashboard/app/components/__tests__/SettingsModal.test.tsx

@@ -17,6 +17,9 @@ const defaultSettings: Settings = {
   buildCommand: "",
   autoResolveConflicts: true,
   smartConflictResolution: true,
+  modelPresets: [],
+  autoSelectModelPreset: false,
+  defaultPresetBySize: {},
   ntfyEnabled: false,
   ntfyTopic: undefined,
   taskStuckTimeoutMs: undefined,
@@ -373,6 +376,55 @@ describe("SettingsModal", () => {
     expect(screen.getAllByText("Model").length).toBeGreaterThanOrEqual(1);
   });
 
+  it("supports creating and saving a model preset", async () => {
+    const user = userEvent.setup();
+    render(<SettingsModal onClose={onClose} addToast={addToast} />);
+    await waitFor(() => expect(fetchSettings).toHaveBeenCalled());
+
+    fireEvent.click(screen.getByText("Model Presets"));
+    await user.click(screen.getByText("Add Preset"));
+
+    await user.type(screen.getByLabelText("Name"), "Budget");
+    expect((screen.getByLabelText("ID") as HTMLInputElement).value).toBe("budget");
+
+    await user.click(screen.getByText("Save preset"));
+    await user.click(screen.getByText("Save"));
+
+    await waitFor(() => expect(updateSettings).toHaveBeenCalledTimes(1));
+    const payload = (updateSettings as ReturnType<typeof vi.fn>).mock.calls[0][0];
+    expect(payload.modelPresets).toEqual([
+      expect.objectContaining({ id: "budget", name: "Budget" }),
+    ]);
+  });
+
+  it("supports auto-select preset mappings by size", async () => {
+    const user = userEvent.setup();
+    (fetchSettings as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      ...defaultSettings,
+      modelPresets: [
+        { id: "budget", name: "Budget" },
+        { id: "normal", name: "Normal" },
+        { id: "complex", name: "Complex" },
+      ],
+    });
+
+    render(<SettingsModal onClose={onClose} addToast={addToast} />);
+    await waitFor(() => expect(fetchSettings).toHaveBeenCalled());
+
+    fireEvent.click(screen.getByText("Model Presets"));
+    await user.click(screen.getByLabelText("Auto-select preset based on task size"));
+    fireEvent.change(screen.getByLabelText("Small tasks (S):"), { target: { value: "budget" } });
+    fireEvent.change(screen.getByLabelText("Medium tasks (M):"), { target: { value: "normal" } });
+    fireEvent.change(screen.getByLabelText("Large tasks (L):"), { target: { value: "complex" } });
+
+    await user.click(screen.getByText("Save"));
+
+    await waitFor(() => expect(updateSettings).toHaveBeenCalledTimes(1));
+    const payload = (updateSettings as ReturnType<typeof vi.fn>).mock.calls[0][0];
+    expect(payload.autoSelectModelPreset).toBe(true);
+    expect(payload.defaultPresetBySize).toEqual({ S: "budget", M: "normal", L: "complex" });
+  });
+
   it("shows model selector with available models grouped by provider", async () => {
     const user = userEvent.setup();
     render(<SettingsModal onClose={onClose} addToast={addToast} />);