Add Reddit monitoring bot — backend, frontend, and Docker config

Python/FastAPI backend with PostgreSQL for collecting Reddit data via
public .json endpoints. React/Vite dashboard for analytics. Docker Compose
setup with API and worker services connecting to shared PostgreSQL.

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

backend/models/__init__.py

@@ -0,0 +1,19 @@
+from backend.models.base import Base
+from backend.models.subreddit import MonitoredSubreddit
+from backend.models.author import Author
+from backend.models.post import Post
+from backend.models.comment import Comment
+from backend.models.metric_snapshot import MetricSnapshot
+from backend.models.daily_digest import DailyDigest
+from backend.models.summary import Summary
+
+__all__ = [
+    "Base",
+    "MonitoredSubreddit",
+    "Author",
+    "Post",
+    "Comment",
+    "MetricSnapshot",
+    "DailyDigest",
+    "Summary",
+]