feat: add agent tools for querying and managing filter rules and rule groups

- Add tools for querying built-in and custom filter rules, and for adding, updating, and deleting custom rules and rule groups
- Refactor filter module to use shared builtin rule definitions
- Enhance rule group querying to include syntax guidance and usage references
- Add unittests for agent filter rule tools registration and parsing logic

app/agent/tools/impl/delete_rule_group.py

@@ -0,0 +1,81 @@
+"""删除过滤规则组工具。"""
+
+import json
+from typing import Optional, Type
+
+from pydantic import BaseModel, Field
+
+from app.agent.tools.base import MoviePilotTool
+from app.agent.tools.impl._filter_rule_utils import (
+    get_rule_groups,
+    remove_rule_group_references,
+    save_system_config,
+)
+from app.log import logger
+from app.schemas.types import SystemConfigKey
+
+
+class DeleteRuleGroupInput(BaseModel):
+    """删除过滤规则组工具的输入参数模型"""
+
+    explanation: str = Field(
+        ...,
+        description="Clear explanation of why this tool is being used in the current context",
+    )
+    name: str = Field(..., description="Rule group name to delete.")
+
+
+class DeleteRuleGroupTool(MoviePilotTool):
+    name: str = "delete_rule_group"
+    description: str = (
+        "Delete a filter rule group from UserFilterRuleGroups. "
+        "The tool also removes dangling references from global settings and subscriptions."
+    )
+    args_schema: Type[BaseModel] = DeleteRuleGroupInput
+    require_admin: bool = True
+
+    def get_tool_message(self, **kwargs) -> Optional[str]:
+        return f"删除规则组 {kwargs.get('name', '')}"
+
+    async def run(self, name: str, **kwargs) -> str:
+        logger.info(f"执行工具: {self.name}, name={name}")
+
+        try:
+            rule_groups = get_rule_groups()
+            if not any(group.name == name for group in rule_groups):
+                return json.dumps(
+                    {
+                        "success": False,
+                        "message": f"规则组 '{name}' 不存在",
+                    },
+                    ensure_ascii=False,
+                )
+
+            remaining_groups = [
+                group for group in rule_groups if group.name != name
+            ]
+            await save_system_config(
+                SystemConfigKey.UserFilterRuleGroups,
+                [group.model_dump(exclude_none=True) for group in remaining_groups],
+            )
+            reference_changes = await remove_rule_group_references(name)
+
+            return json.dumps(
+                {
+                    "success": True,
+                    "message": f"已删除规则组 {name}",
+                    "count": len(remaining_groups),
+                    "reference_updates": reference_changes,
+                },
+                ensure_ascii=False,
+                indent=2,
+            )
+        except Exception as exc:
+            logger.error(f"删除规则组失败: {exc}", exc_info=True)
+            return json.dumps(
+                {
+                    "success": False,
+                    "message": f"删除规则组失败: {exc}",
+                },
+                ensure_ascii=False,
+            )