fix(agent): 修复规则中心表格版本和修改记录

补齐规则资产 JSON 读写接口和前端调用，修复 AuditView 导入缺失。

Excel 在线编辑改为比对所有页签并生成最近修改记录，版本快照统一保存到 rules/finance-rules/.versions。

隔离规则表测试存储，避免测试或旧入口写入真实规则目录与 storage/agent_assets。

server/src/app/services/agent_asset_rule_library.py

@@ -0,0 +1,84 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+from typing import Any
+
+from app.core.config import SERVER_DIR
+from app.services.agent_asset_spreadsheet import RULE_LIBRARY_NAMES
+
+JSON_RULE_MIME_TYPE = "application/json"
+
+
+class AgentAssetRuleLibraryManager:
+    def __init__(self, rule_root: Path | None = None) -> None:
+        self.rule_root = Path(rule_root or (SERVER_DIR / "rules")).resolve()
+
+    def ensure_rule_library_dirs(self) -> None:
+        for library in sorted(RULE_LIBRARY_NAMES):
+            (self.rule_root / library).mkdir(parents=True, exist_ok=True)
+
+    def resolve_rule_library_path(self, *, library: str, file_name: str) -> Path:
+        normalized_library = str(library or "").strip()
+        if normalized_library not in RULE_LIBRARY_NAMES:
+            raise ValueError("Invalid rule library.")
+
+        normalized_name = Path(str(file_name or "").strip()).name.strip()
+        if not normalized_name or not normalized_name.endswith(".json"):
+            raise ValueError("Rule JSON file name must end with .json.")
+
+        library_dir = (self.rule_root / normalized_library).resolve()
+        target_path = (library_dir / normalized_name).resolve()
+        try:
+            target_path.relative_to(library_dir)
+        except ValueError:
+            raise ValueError("Invalid rule JSON path.") from None
+        return target_path
+
+    def read_rule_library_json(self, *, library: str, file_name: str) -> dict[str, Any]:
+        target_path = self.resolve_rule_library_path(library=library, file_name=file_name)
+        if not target_path.exists():
+            raise FileNotFoundError("Rule JSON file not found.")
+
+        try:
+            payload = json.loads(target_path.read_text(encoding="utf-8"))
+        except json.JSONDecodeError as exc:
+            raise ValueError("Rule JSON file is invalid.") from exc
+
+        if not isinstance(payload, dict):
+            raise ValueError("Rule JSON payload must be an object.")
+        return payload
+
+    def write_rule_library_json(
+        self,
+        *,
+        library: str,
+        file_name: str,
+        payload: dict[str, Any],
+    ) -> dict[str, Any]:
+        if not isinstance(payload, dict):
+            raise ValueError("Rule JSON payload must be an object.")
+
+        rule_code = str(payload.get("rule_code") or "").strip()
+        if not rule_code:
+            raise ValueError("Rule JSON must include rule_code.")
+
+        evaluator = str(payload.get("evaluator") or "").strip()
+        if not evaluator:
+            raise ValueError("Rule JSON must include evaluator.")
+
+        target_path = self.resolve_rule_library_path(library=library, file_name=file_name)
+        target_path.parent.mkdir(parents=True, exist_ok=True)
+        target_path.write_text(
+            f"{json.dumps(payload, ensure_ascii=False, indent=2)}\n",
+            encoding="utf-8",
+        )
+        return payload
+
+    def list_rule_library_json_files(self, *, library: str) -> list[str]:
+        library_dir = self.resolve_rule_library_path(
+            library=library,
+            file_name="placeholder.json",
+        ).parent
+        library_dir.mkdir(parents=True, exist_ok=True)
+        return sorted(path.name for path in library_dir.glob("*.json") if path.is_file())