[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/config.py

@@ -0,0 +1,20 @@
+from functools import lru_cache
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")
+
+    database_url: str
+    s3_endpoint_url: str
+    s3_bucket_name: str
+    s3_access_key_id: str
+    s3_secret_access_key: str
+    s3_region: str = "us-east-1"
+    api_base_url: str = "http://localhost:8000"
+    max_upload_bytes: int = 52_428_800  # 50 MiB
+
+
+@lru_cache
+def get_settings() -> Settings:
+    return Settings()