feat(web): 立项新增 基调/结局/视角 三字段（书级常量入 stable_core 缓存前缀）

灵感计划 §3④ + §4 D 枚举决策：
- projects 表加 tone/ending_type/narrative_pov（Text nullable、无 CHECK，同 genre/structure；
  迁移 e5f6a7b8c9d0 nullable 免 backfill）。
- ProjectCreateRequest/ProjectResponse + domain ProjectCreate/ProjectView 全链路透传（snake_case）。
- 完整 stable_core 链路：ProjectSpecView + SqlProjectSpecRepo.spec + _build_spec_section 渲染进
  「作品蓝本」块——书级常量随书稳定，字节稳定守缓存前缀不变量 #9，绝不入 volatile。
- 前端 wizard.ts 三字段 + 预设数组 TONES/ENDING_TYPES/NARRATIVE_POVS + ProjectWizard 控件与确认页回显。
- 契约变更已 pnpm gen:api + memory/contracts.md 登记。

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

@@ -57,6 +57,9 @@ describe("toCreateRequest", () => {
       premise: "  ",
       protagonist: "",
       theme: "抗争",
+      tone: "",
+      endingType: "",
+      narrativePov: "",
     };
     expect(toCreateRequest(form)).toEqual({
       title: "逐光而行",
@@ -66,9 +69,34 @@ describe("toCreateRequest", () => {
       theme: "抗争",
       selling_points: ["逆袭", "系统流"],
       structure: "三幕",
+      tone: null,
+      ending_type: null,
+      narrative_pov: null,
     });
   });
 
+  // ④ 立项新增基调/结局/视角：camelCase 表单 → snake_case 请求，空值落 null。
+  it("maps tone, endingType, narrativePov to snake_case fields", () => {
+    const form: WizardForm = {
+      ...emptyWizardForm,
+      title: "书",
+      tone: "热血",
+      endingType: "HE",
+      narrativePov: "第一人称",
+    };
+    const req = toCreateRequest(form);
+    expect(req.tone).toBe("热血");
+    expect(req.ending_type).toBe("HE");
+    expect(req.narrative_pov).toBe("第一人称");
+  });
+
+  it("nulls empty tone, endingType, narrativePov", () => {
+    const req = toCreateRequest({ ...emptyWizardForm, title: "书" });
+    expect(req.tone).toBeNull();
+    expect(req.ending_type).toBeNull();
+    expect(req.narrative_pov).toBeNull();
+  });
+
   // QA H1 回归：立意（premise）与主角/金手指（protagonist）是两个独立输入，
   // 不能互相覆盖——提交时各占一段合并进 premise。
   it("merges premise and protagonist into premise without overwriting", () => {