feat(web): AI 立项方案生成+预填（种子门控 + 按字段接受）

向导阶段（project 未建）一键推演结构化书级蓝图预填立项向导。

- 新 SPEC project_plan_spec（analyst 档，纯预览 reads/writes=()）+ schema
  ProjectPlanResult（书名候选 + 时空背景/叙事结构/故事核心/结局设计/基调，
  全字段默认值守解析韧性）+ 注册 SCHEMA_CATALOG；计数三处 21→22 + regen golden。
- 端点 POST /skills/project-plan/generate（不带 project 前缀，绕开 toolbox 404）：
  请求体序列化向导草稿为 project_context，复用 build_brief_context + run_generator；
  种子门控（缺 genre/logline→422）；请求 schema 加 max_length 上界。
- run_generator/_build_request 的 project_id 放宽 uuid.UUID|None（向导无 project）。
- 前端 wizard.ts 加 mapPlanResultToWizardForm（错配字段折进 premise 不静默丢）+
  applyPlanPatch（仅回填空字段、保护已编辑）+ useProjectPlan hook + PlanAssistant。

apps/web/lib/wizard/useProjectPlan.test.ts

@@ -0,0 +1,95 @@
+// @vitest-environment jsdom
+import { act, renderHook } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import type { ProjectPlanGenerateRequest } from "@/lib/api/types";
+
+import { useProjectPlan } from "./useProjectPlan";
+
+// 后端客户端与 Toast 是 hook 的外部副作用边界，单测一律 mock。
+const post = vi.fn();
+const toast = vi.fn();
+vi.mock("@/lib/api/client", () => ({ api: { POST: (...a: unknown[]) => post(...a) } }));
+vi.mock("@/components/Toast", () => ({ useToast: () => toast }));
+
+const seed: ProjectPlanGenerateRequest = {
+  genre: "仙侠",
+  logline: "废柴逆袭封神。",
+};
+
+describe("useProjectPlan", () => {
+  beforeEach(() => {
+    post.mockReset();
+    toast.mockReset();
+  });
+  afterEach(() => vi.clearAllMocks());
+
+  it("初始为 idle、无方案", () => {
+    const { result } = renderHook(() => useProjectPlan());
+    expect(result.current.status).toBe("idle");
+    expect(result.current.plan).toBeNull();
+  });
+
+  it("生成成功：status 走到 done 并填充方案", async () => {
+    const plan = {
+      title_candidates: ["逐光而行"],
+      setting: "仙门世界",
+      narrative_structure: "立钩",
+      story_core: "逆袭",
+      ending_design: "归隐",
+      tone: "热血",
+    };
+    post.mockResolvedValue({ data: plan, error: null });
+
+    const { result } = renderHook(() => useProjectPlan());
+    await act(async () => {
+      await result.current.generate(seed);
+    });
+
+    expect(result.current.status).toBe("done");
+    expect(result.current.plan).toEqual(plan);
+    expect(toast).not.toHaveBeenCalled();
+  });
+
+  it("后端返回 error：status=error 且弹错误 toast", async () => {
+    post.mockResolvedValue({ data: null, error: { detail: "配额不足" } });
+    const { result } = renderHook(() => useProjectPlan());
+    await act(async () => {
+      await result.current.generate(seed);
+    });
+    expect(result.current.status).toBe("error");
+    expect(result.current.plan).toBeNull();
+    expect(toast).toHaveBeenCalledWith(expect.any(String), "error");
+  });
+
+  it("请求抛异常：status=error 且弹网络异常 toast", async () => {
+    post.mockRejectedValue(new Error("network down"));
+    const { result } = renderHook(() => useProjectPlan());
+    await act(async () => {
+      await result.current.generate(seed);
+    });
+    expect(result.current.status).toBe("error");
+    expect(toast).toHaveBeenCalledWith("生成请求异常，请检查网络。", "error");
+  });
+
+  it("reset 清回 idle 与空方案", async () => {
+    post.mockResolvedValue({
+      data: {
+        title_candidates: ["书"],
+        setting: "",
+        narrative_structure: "",
+        story_core: "",
+        ending_design: "",
+        tone: "",
+      },
+      error: null,
+    });
+    const { result } = renderHook(() => useProjectPlan());
+    await act(async () => {
+      await result.current.generate(seed);
+    });
+    act(() => result.current.reset());
+    expect(result.current.status).toBe("idle");
+    expect(result.current.plan).toBeNull();
+  });
+});