[Spec Kit] Implementation progress

Implements all 88 tasks for the Reaction Image Board (specs/001-reaction-image-board):

- docker-compose.yml: postgres, minio, minio-init, api, ui services with healthchecks
- api/: FastAPI app with SQLAlchemy 2.x async, Alembic migrations, S3/MinIO storage,
  full integration + unit test suite (pytest + pytest-asyncio)
- ui/: Angular 19 standalone app (Library, Upload, Detail, NotFound components)
- .env.example: all required environment variables
- .gitignore: Python, Node, Docker, IDE, .env patterns

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/app/repositories/image_repo.py

@@ -0,0 +1,84 @@
+import uuid
+from typing import Optional
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.models import Image, ImageTag, Tag
+
+
+class ImageRepository:
+    def __init__(self, session: AsyncSession) -> None:
+        self._session = session
+
+    async def get_by_hash(self, hash_hex: str) -> Optional[Image]:
+        result = await self._session.execute(
+            select(Image).where(Image.hash == hash_hex).options(selectinload(Image.image_tags).selectinload(ImageTag.tag))
+        )
+        return result.scalar_one_or_none()
+
+    async def get_by_id(self, image_id: uuid.UUID) -> Optional[Image]:
+        result = await self._session.execute(
+            select(Image).where(Image.id == image_id).options(selectinload(Image.image_tags).selectinload(ImageTag.tag))
+        )
+        return result.scalar_one_or_none()
+
+    async def create(
+        self,
+        *,
+        hash_hex: str,
+        filename: str,
+        mime_type: str,
+        size_bytes: int,
+        width: int,
+        height: int,
+        storage_key: str,
+    ) -> Image:
+        image = Image(
+            hash=hash_hex,
+            filename=filename,
+            mime_type=mime_type,
+            size_bytes=size_bytes,
+            width=width,
+            height=height,
+            storage_key=storage_key,
+        )
+        self._session.add(image)
+        await self._session.flush()
+        await self._session.refresh(image, ["image_tags"])
+        return image
+
+    async def list_images(
+        self,
+        tag_names: list[str] | None = None,
+        limit: int = 50,
+        offset: int = 0,
+    ) -> tuple[list[Image], int]:
+        from sqlalchemy import func, and_
+
+        base_query = select(Image).options(
+            selectinload(Image.image_tags).selectinload(ImageTag.tag)
+        )
+
+        if tag_names:
+            for tag_name in tag_names:
+                subq = (
+                    select(ImageTag.image_id)
+                    .join(Tag, ImageTag.tag_id == Tag.id)
+                    .where(Tag.name == tag_name)
+                    .scalar_subquery()
+                )
+                base_query = base_query.where(Image.id.in_(subq))
+
+        count_query = select(func.count()).select_from(base_query.subquery())
+        total_result = await self._session.execute(count_query)
+        total = total_result.scalar_one()
+
+        paginated = base_query.order_by(Image.created_at.desc()).limit(limit).offset(offset)
+        result = await self._session.execute(paginated)
+        return result.scalars().all(), total
+
+    async def delete(self, image: Image) -> None:
+        await self._session.delete(image)
+        await self._session.flush()