feat: PromptRegistry 注册/版本/渲染（jinja2）

_AI_USAGE_LOG.md

@@ -44,3 +44,4 @@
 | 2026-08-09 下午 | Agent 实现 | 里程碑3.1 实施计划生成（writing-plans）：5 任务 TDD 计划落盘 docs/superpowers/plans/2026-08-09-inference-engine.md——Task1 types+exceptions+依赖(httpx/jinja2)、Task2 token(approximate/tiktoken可选)、Task3 PromptRegistry(jinja2)、Task4 HttpLLMClient(重试/退避/超时/鉴权)、Task5 InferenceEngine(chat/chat_structured全流程+注入Fake+文档补丁)；修正 helper 导入、方法名(_call)、结构化状态语义(重试成功仍ok) | docs/superpowers/plans/2026-08-09-inference-engine.md, _AI_USAGE_LOG.md | deepseek-v4-flash-free |
 | 2026-08-09 05:53 | Agent 实现 | 里程碑3.1 Task1 实现：推理引擎数据模型与异常层。新建 src/genesis/inference/（__init__/types/exceptions：TokenUsage、ChatMessage、ChatResult、StructuredResult、Prompt 五 dataclass 与 LLMError 体系五异常，__init__ 暂不导入 engine/client 防循环）；pyproject.toml 增加 httpx>=0.28/jinja2>=3.1 依赖；tests/test_inference_types.py（6 用例）与 tests/test_inference_errors.py（2 用例）；TDD 验证 RED（ModuleNotFoundError: No module named 'genesis.inference'）→ GREEN（聚焦 8 passed）；pytest 全量 79 passed 覆盖 100.00%（608 stmts/140 br），fail_under=99 达标；提交见 git log | src/genesis/inference/__init__.py, src/genesis/inference/types.py, src/genesis/inference/exceptions.py, pyproject.toml, tests/test_inference_types.py, tests/test_inference_errors.py, _AI_USAGE_LOG.md | deepseek-v4-flash-free |
 | 2026-08-09 05:57 | Agent 实现 | 里程碑3.1 Task2 实现：推理引擎 token 估算模块。新建 src/genesis/inference/token.py（approximate_token_count 每 4 字符≈1 token 最少 1、_tiktoken_estimator tiktoken 编码未安装返回 None、make_estimator backend="tiktoken" 默认优先 tiktoken 缺失回落 approximate）；tests/test_inference_token.py 按 brief 5 用例 + 补充 2 用例（假 tiktoken 成功路径、encoding 抛异常回落）覆盖 tiktoken 成功/异常两分支，保证全量覆盖不回落；TDD 验证 RED（ModuleNotFoundError: No module named 'genesis.inference.token'）→ 聚焦 7 passed，token.py 100%；pytest 全量 86 passed 覆盖 100.00%（626 stmts/142 br）；提交见 git log | src/genesis/inference/token.py, tests/test_inference_token.py, _AI_USAGE_LOG.md | deepseek-v4-flash-free |
+| 2026-08-09 08:02 | Agent 实现 | 里程碑3.1 Task3 实现：Prompt 注册表。新建 src/genesis/inference/prompt_registry.py（PromptRegistry：register/get/list_versions/render，version=None 取最新，jinja2 渲染，name/name@version 缺失抛 KeyError）；tests/test_inference_prompt_registry.py 按 brief 5 用例 + 补 1 用例（指定不存在的 version 抛 KeyError，覆盖 get 中 key not in templates 分支）；TDD 验证 RED（ModuleNotFoundError: No module named genesis.inference.prompt_registry）→ GREEN（聚焦 6 passed）；pytest 全量 92 passed 覆盖 100.00%（653 stmts/150 br），fail_under=99 达标 | src/genesis/inference/prompt_registry.py, tests/test_inference_prompt_registry.py, _AI_USAGE_LOG.md | deepseek-v4-flash-free |

src/genesis/inference/prompt_registry.py

@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+from typing import Any
+
+from jinja2 import Template
+
+from .types import Prompt
+
+
+class PromptRegistry:
+    """Prompt 模板库：注册/取用/版本管理/渲染（集中管理待迁移 prompts/ 目录）。"""
+
+    def __init__(self) -> None:
+        self._templates: dict[tuple[str, str], str] = {}
+
+    def register(self, name: str, version: str, template: str) -> None:
+        """注册（或覆盖）一个版本的模板。"""
+        self._templates[(name, version)] = template
+
+    def get(
+        self,
+        name: str,
+        version: str | None = None,
+        variables: dict[str, Any] | None = None,
+    ) -> str:
+        """取模板；version=None 返回该 name 最新注册版本；variables 非空时渲染。"""
+        if version is None:
+            versions = self.list_versions(name)
+            if not versions:
+                raise KeyError(f"prompt not found: {name}")
+            version = versions[-1]
+        key = (name, version)
+        if key not in self._templates:
+            raise KeyError(f"prompt version not found: {name}@{version}")
+        template = self._templates[key]
+        if variables:
+            return self.render(template, variables)
+        return template
+
+    def list_versions(self, name: str) -> list[str]:
+        """返回某 name 的已注册版本（按注册顺序）。"""
+        return [v for (n, v) in self._templates if n == name]
+
+    def render(self, template: str, variables: dict[str, Any]) -> str:
+        """用 jinja2 渲染模板。"""
+        from jinja2 import Template
+
+        return Template(template).render(**variables)

tests/test_inference_prompt_registry.py

@@ -0,0 +1,42 @@
+import pytest
+
+from genesis.inference.prompt_registry import PromptRegistry
+from genesis.inference.types import Prompt
+
+
+def test_register_and_render():
+    reg = PromptRegistry()
+    reg.register("writer", "v1", "按规则撰写：{{ chapter }}")
+    assert reg.get("writer", "v1") == "按规则撰写：{{ chapter }}"
+
+
+def test_get_with_variables_renders():
+    reg = PromptRegistry()
+    reg.register("writer", "v1", "按规则撰写：{{ chapter }}")
+    assert reg.get("writer", "v1", {"chapter": "帳票設計"}) == "按规则撰写：帳票設計"
+
+
+def test_get_latest_version():
+    reg = PromptRegistry()
+    reg.register("writer", "v1", "t1")
+    reg.register("writer", "v2", "t2")
+    assert reg.get("writer") == "t2"
+    assert reg.list_versions("writer") == ["v1", "v2"]
+
+
+def test_get_missing_raises_keyerror():
+    reg = PromptRegistry()
+    with pytest.raises(KeyError):
+        reg.get("dne")
+
+
+def test_get_missing_version_raises_keyerror():
+    reg = PromptRegistry()
+    reg.register("writer", "v1", "t1")
+    with pytest.raises(KeyError):
+        reg.get("writer", "v9")
+
+
+def test_render_raw():
+    reg = PromptRegistry()
+    assert reg.render("{{ a }} と {{ b }}", {"a": "x", "b": 1}) == "x と 1"