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>

packages/llm_gateway/tests/fakes_resilience.py

@@ -0,0 +1,119 @@
+"""T5.4 韧性测试替身（多 provider 适配器 + 失败模拟 + 记账嗅探）——绝不联网。
+
+放独立模块（非 conftest），测试走绝对导入 `from fakes_resilience import ...`。
+本目录无 __init__.py（见 fakes.py 注释）。
+"""
+
+from __future__ import annotations
+
+from collections.abc import AsyncIterator, Callable
+
+from ww_llm_gateway.adapters.base import (
+    Capabilities,
+    ProviderResult,
+    ProviderUsage,
+    StreamChunk,
+)
+from ww_llm_gateway.errors import TransientProviderError
+from ww_llm_gateway.routing import Route
+from ww_llm_gateway.types import LlmRequest, Scope, Tier, Usage
+
+
+class ScriptedAdapter:
+    """可编排成功/失败序列的假适配器。
+
+    `failures` 为开头要抛的异常列表（每次 complete/stream 消费一个）；耗尽后正常返回。
+    `capabilities_` 控制能力矩阵（测降级）。记录调用次数以断言回退/重试行为。
+    """
+
+    def __init__(
+        self,
+        provider: str,
+        *,
+        text: str = "ok",
+        failures: list[Exception] | None = None,
+        capabilities_: Capabilities | None = None,
+        input_tokens: int = 100,
+        output_tokens: int = 50,
+        structured_text: str | None = None,
+    ) -> None:
+        self.provider = provider
+        self.text = text
+        self._failures = list(failures or [])
+        self._caps = capabilities_ or Capabilities(structured_output=True, prefix_cache=True)
+        self.input_tokens = input_tokens
+        self.output_tokens = output_tokens
+        self.structured_text = structured_text
+        self.complete_calls = 0
+        self.stream_calls = 0
+
+    def capabilities(self) -> Capabilities:
+        return self._caps
+
+    def _maybe_fail(self) -> None:
+        if self._failures:
+            raise self._failures.pop(0)
+
+    async def complete(self, req: LlmRequest, model: str) -> ProviderResult:
+        self.complete_calls += 1
+        self._maybe_fail()
+        if req.output_schema is not None:
+            # 模拟原生结构化输出：仅当能力声明支持时才会被网关派到这里。
+            parsed = req.output_schema.model_validate({} if not _has_fields(req) else _stub(req))
+            return ProviderResult(
+                text=parsed.model_dump_json(),
+                usage=ProviderUsage(
+                    input_tokens=self.input_tokens, output_tokens=self.output_tokens
+                ),
+                parsed=parsed,
+            )
+        return ProviderResult(
+            text=self.structured_text or self.text,
+            usage=ProviderUsage(input_tokens=self.input_tokens, output_tokens=self.output_tokens),
+        )
+
+    async def stream(self, req: LlmRequest, model: str) -> AsyncIterator[StreamChunk]:
+        self.stream_calls += 1
+        self._maybe_fail()
+        for ch in self.text:
+            yield StreamChunk(text=ch)
+        yield StreamChunk(
+            usage=ProviderUsage(input_tokens=self.input_tokens, output_tokens=self.output_tokens)
+        )
+
+
+def _has_fields(req: LlmRequest) -> bool:
+    return bool(req.output_schema and req.output_schema.model_fields)
+
+
+def _stub(req: LlmRequest) -> dict[str, object]:
+    # 用各字段默认/最小填充——测试 schema 仅需可构造。
+    assert req.output_schema is not None
+    out: dict[str, object] = {}
+    for name, field in req.output_schema.model_fields.items():
+        if field.is_required():
+            out[name] = "x"
+    return out
+
+
+class FakeLedger:
+    def __init__(self) -> None:
+        self.records: list[Usage] = []
+
+    async def record(self, scope: Scope, usage: Usage) -> None:
+        self.records.append(usage)
+
+
+def transient(msg: str = "boom") -> TransientProviderError:
+    return TransientProviderError(msg)
+
+
+def chain(*routes: tuple[str, str]) -> list[Route]:
+    return [Route(provider=p, model=m) for p, m in routes]
+
+
+def chain_resolver(routes: list[Route]) -> Callable[[Tier], list[Route]]:
+    def _resolve(tier: Tier) -> list[Route]:
+        return routes
+
+    return _resolve