feat: add AirShelf core implementation

core/backend/apps/ai/providers/base.py

@@ -0,0 +1,19 @@
+from dataclasses import dataclass, field
+from typing import Any, Protocol
+
+
+@dataclass(frozen=True)
+class AIProviderResult:
+    provider_task_id: str = ""
+    status: str = "succeeded"
+    payload: dict[str, Any] = field(default_factory=dict)
+    asset_urls: list[str] = field(default_factory=list)
+
+
+class AIProvider(Protocol):
+    def submit(self, payload: dict[str, Any]) -> AIProviderResult:
+        ...
+
+    def poll(self, provider_task_id: str) -> AIProviderResult:
+        ...
+