feat: add resource library and real image workflow

app/infra/image_generation/base.py

@@ -0,0 +1,38 @@
+"""Shared types for image-generation providers."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Protocol
+
+
+@dataclass(slots=True)
+class SourceImage:
+    """A binary source image passed into an image-generation provider."""
+
+    url: str
+    mime_type: str
+    data: bytes
+
+
+@dataclass(slots=True)
+class GeneratedImageResult:
+    """Normalized image-generation output returned by providers."""
+
+    image_bytes: bytes
+    mime_type: str
+    provider: str
+    model: str
+    prompt: str
+
+
+class ImageGenerationProvider(Protocol):
+    """Contract implemented by concrete image-generation providers."""
+
+    async def generate_tryon_image(
+        self,
+        *,
+        prompt: str,
+        person_image: SourceImage,
+        garment_image: SourceImage,
+    ) -> GeneratedImageResult: ...