feat: M4 文风 + M5 生成/多provider/Skill + Kimi Code 订阅接入 + 本地联调修复

M4（文风）: style-auditor 双轨（提取指纹/漂移第四审）+ jobs 长任务框架(zombie reaper) + 回炉 refine + GET /style read-back。
M5（生成+扩展）: worldbuilder/character-gen（入库 continuity 409 gate + partition_writes 白名单 + schema→JSONB 形变）；
  网关多 provider 回退链/熔断/能力降级（Anthropic/Gemini 适配器）；Skill registry + 表权限沙箱 + 规则；
  前端 角色生成器/世界观/Codex/规则页/技能库/⌘K 命令面板。
K1（Kimi Code 订阅接入）: OAuth device-flow（kimi-code）+ 静态 Console key（kimi-code-key）两路径；
  coding 端点 KimiCLI 伪造头（实测 UA allow-list 门禁，缺则 403）+ JSON 模式结构化（thinking ⊥ tool_choice）。
本地联调修复: CORS 中间件；assemble 注入 premise+「写第N章」指令（修空 prompt 400）；
  GET /outline·/draft read-back + 大纲/工作台/审稿页重载；写页 client/server 常量边界 + notFound 健壮化；
  字数 toLocaleString locale 水合；审稿页终稿从已存草稿 seed（修 accept 422）。
门禁: backend ruff/mypy(157)/alembic 无漂移/pytest 451 · frontend lint/tsc/vitest/build。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/lib/settings/providers.test.ts

@@ -0,0 +1,107 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  API_KEY_PROVIDERS,
+  KNOWN_PROVIDERS,
+  applyProviderChange,
+  defaultModelFor,
+  draftsToRoutingInput,
+  toRoutingDrafts,
+  type RoutingDraft,
+} from "./providers";
+
+describe("KNOWN_PROVIDERS", () => {
+  it("includes kimi-code as an OAuth provider with a fixed model", () => {
+    const kc = KNOWN_PROVIDERS.find((p) => p.id === "kimi-code");
+    expect(kc).toBeDefined();
+    expect(kc?.auth).toBe("oauth");
+    expect(kc?.defaultModel).toBe("kimi-for-coding");
+  });
+
+  it("API_KEY_PROVIDERS excludes the OAuth provider", () => {
+    expect(API_KEY_PROVIDERS.some((p) => p.id === "kimi-code")).toBe(false);
+    expect(API_KEY_PROVIDERS.some((p) => p.id === "deepseek")).toBe(true);
+  });
+
+  it("includes kimi-code-key as an api_key provider with a fixed model", () => {
+    const kck = KNOWN_PROVIDERS.find((p) => p.id === "kimi-code-key");
+    expect(kck).toBeDefined();
+    expect(kck?.auth).toBe("api_key");
+    expect(kck?.defaultModel).toBe("kimi-for-coding");
+  });
+
+  it("API_KEY_PROVIDERS includes the static-key Kimi Code provider", () => {
+    expect(API_KEY_PROVIDERS.some((p) => p.id === "kimi-code-key")).toBe(true);
+  });
+});
+
+describe("defaultModelFor", () => {
+  it("returns the OAuth provider's fixed model", () => {
+    expect(defaultModelFor("kimi-code")).toBe("kimi-for-coding");
+  });
+
+  it("returns the static-key Kimi Code provider's fixed model", () => {
+    expect(defaultModelFor("kimi-code-key")).toBe("kimi-for-coding");
+  });
+
+  it("returns empty string for api_key providers / unknown", () => {
+    expect(defaultModelFor("deepseek")).toBe("");
+    expect(defaultModelFor("nope")).toBe("");
+  });
+});
+
+describe("toRoutingDrafts", () => {
+  it("expands to all tiers, filling missing ones empty", () => {
+    const drafts = toRoutingDrafts([
+      { tier: "writer", provider: "deepseek", model: "deepseek-chat" },
+    ]);
+    expect(drafts.map((d) => d.tier)).toEqual(["writer", "analyst", "light"]);
+    expect(drafts[0]).toEqual({
+      tier: "writer",
+      provider: "deepseek",
+      model: "deepseek-chat",
+    });
+    expect(drafts[1]).toEqual({ tier: "analyst", provider: "", model: "" });
+  });
+});
+
+describe("applyProviderChange", () => {
+  it("auto-fills the OAuth provider's fixed model", () => {
+    const next = applyProviderChange(
+      { tier: "writer", provider: "", model: "" },
+      "kimi-code",
+    );
+    expect(next).toEqual({
+      tier: "writer",
+      provider: "kimi-code",
+      model: "kimi-for-coding",
+    });
+  });
+
+  it("clears the model when switching to an api_key provider", () => {
+    const next = applyProviderChange(
+      { tier: "writer", provider: "kimi-code", model: "kimi-for-coding" },
+      "deepseek",
+    );
+    expect(next).toEqual({ tier: "writer", provider: "deepseek", model: "" });
+  });
+
+  it("does not mutate the input draft", () => {
+    const draft: RoutingDraft = { tier: "writer", provider: "", model: "" };
+    applyProviderChange(draft, "kimi-code");
+    expect(draft).toEqual({ tier: "writer", provider: "", model: "" });
+  });
+});
+
+describe("draftsToRoutingInput", () => {
+  it("keeps only rows with both provider and model", () => {
+    const input = draftsToRoutingInput([
+      { tier: "writer", provider: "kimi-code", model: "kimi-for-coding" },
+      { tier: "analyst", provider: "", model: "" },
+      { tier: "light", provider: "deepseek", model: "" },
+    ]);
+    expect(input).toEqual([
+      { tier: "writer", provider: "kimi-code", model: "kimi-for-coding" },
+    ]);
+  });
+});