feat: 多平台 Coding Plan 统一管理系统初始实现

- 支持 MiniMax/OpenAI/Google Gemini/智谱/Kimi 五个平台
- 插件化 Provider 架构，自动发现注册
- 多维度 QuotaRule 额度追踪（固定间隔/自然周期/API同步/手动）
- OpenAI + Anthropic 兼容 API 代理，SSE 流式转发
- Model 路由表 + 额度耗尽自动 fallback
- 多媒体任务队列（图片/语音/视频）
- Vue3 + Tailwind 单文件 Web 仪表盘
- Docker 一键部署

Made-with: Cursor

app/providers/base.py

@@ -0,0 +1,87 @@
+"""Provider 抽象基类 + 能力枚举"""
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from enum import Enum
+from typing import Any, AsyncGenerator
+
+from pydantic import BaseModel
+
+
+class Capability(str, Enum):
+    CHAT = "chat"
+    IMAGE = "image"
+    VOICE = "voice"
+    VIDEO = "video"
+    FILE = "file"
+    EMBEDDING = "embedding"
+
+
+class QuotaInfo(BaseModel):
+    """Provider 返回的额度信息"""
+    quota_used: int = 0
+    quota_remaining: int = 0
+    quota_total: int = 0
+    unit: str = "tokens"
+    raw: dict[str, Any] | None = None
+
+
+class BaseProvider(ABC):
+    """
+    所有平台适配器的基类。
+    子类需要设置 name / display_name / capabilities，
+    并实现对应能力的方法。
+    """
+    name: str = ""
+    display_name: str = ""
+    capabilities: list[Capability] = []
+
+    @abstractmethod
+    async def chat(
+        self,
+        messages: list[dict],
+        model: str,
+        plan: dict,
+        stream: bool = True,
+        **kwargs,
+    ) -> AsyncGenerator[str, None]:
+        """
+        聊天补全。返回 SSE 格式的 data 行。
+        每 yield 一次代表一个 SSE event 的 data 字段内容。
+        """
+        yield ""  # pragma: no cover
+
+    async def generate_image(
+        self, prompt: str, plan: dict, **kwargs
+    ) -> dict[str, Any]:
+        raise NotImplementedError(f"{self.name} does not support image generation")
+
+    async def generate_voice(
+        self, text: str, plan: dict, **kwargs
+    ) -> bytes:
+        raise NotImplementedError(f"{self.name} does not support voice synthesis")
+
+    async def generate_video(
+        self, prompt: str, plan: dict, **kwargs
+    ) -> dict[str, Any]:
+        raise NotImplementedError(f"{self.name} does not support video generation")
+
+    async def query_quota(self, plan: dict) -> QuotaInfo | None:
+        """
+        查询平台额度。返回 None 表示该平台不支持 API 查询，走本地追踪。
+        """
+        return None
+
+    def _build_headers(self, plan: dict) -> dict[str, str]:
+        """构建请求头: Authorization + extra_headers"""
+        headers = {"Content-Type": "application/json"}
+        api_key = plan.get("api_key", "")
+        if api_key:
+            headers["Authorization"] = f"Bearer {api_key}"
+        extra = plan.get("extra_headers") or {}
+        headers.update(extra)
+        return headers
+
+    def _base_url(self, plan: dict) -> str:
+        return (plan.get("api_base") or "").rstrip("/")