[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/models.py

@@ -0,0 +1,61 @@
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import String, Integer, BigInteger, DateTime, ForeignKey, UniqueConstraint, Index
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+def _utcnow() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+class Image(Base):
+    __tablename__ = "images"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    hash: Mapped[str] = mapped_column(String(64), unique=True, nullable=False, index=True)
+    filename: Mapped[str] = mapped_column(String, nullable=False)
+    mime_type: Mapped[str] = mapped_column(String(20), nullable=False)
+    size_bytes: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    width: Mapped[int] = mapped_column(Integer, nullable=False)
+    height: Mapped[int] = mapped_column(Integer, nullable=False)
+    storage_key: Mapped[str] = mapped_column(String(64), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, nullable=False)
+
+    image_tags: Mapped[list["ImageTag"]] = relationship(back_populates="image", cascade="all, delete-orphan")
+
+    @property
+    def tags(self) -> list[str]:
+        return [it.tag.name for it in self.image_tags if it.tag]
+
+
+class Tag(Base):
+    __tablename__ = "tags"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(64), unique=True, nullable=False, index=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_utcnow, nullable=False)
+
+    image_tags: Mapped[list["ImageTag"]] = relationship(back_populates="tag")
+
+
+class ImageTag(Base):
+    __tablename__ = "image_tags"
+    __table_args__ = (
+        UniqueConstraint("image_id", "tag_id", name="uq_image_tag"),
+        Index("ix_image_tags_image_id", "image_id"),
+        Index("ix_image_tags_tag_id", "tag_id"),
+    )
+
+    image_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("images.id", ondelete="CASCADE"), primary_key=True
+    )
+    tag_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("tags.id", ondelete="RESTRICT"), primary_key=True
+    )
+
+    image: Mapped["Image"] = relationship(back_populates="image_tags")
+    tag: Mapped["Tag"] = relationship(back_populates="image_tags")