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/routers/analytics.py

@@ -0,0 +1,61 @@
+from datetime import datetime
+from fastapi import APIRouter, Depends, Query
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from backend.database import get_db
+from backend.services import analytics_service
+
+router = APIRouter(prefix="/analytics", tags=["analytics"])
+
+
+@router.get("/engagement")
+async def engagement(
+    subreddit_id: int | None = None,
+    granularity: str = Query("day", pattern="^(hour|day|week)$"),
+    since: datetime | None = None,
+    until: datetime | None = None,
+    db: AsyncSession = Depends(get_db),
+):
+    return await analytics_service.get_engagement(db, subreddit_id, granularity, since, until)
+
+
+@router.get("/top-posts")
+async def top_posts(
+    subreddit_id: int | None = None,
+    metric: str = Query("score", pattern="^(score|num_comments)$"),
+    since: datetime | None = None,
+    until: datetime | None = None,
+    limit: int = Query(10, ge=1, le=50),
+    db: AsyncSession = Depends(get_db),
+):
+    return await analytics_service.get_top_posts(db, subreddit_id, metric, since, until, limit)
+
+
+@router.get("/top-authors")
+async def top_authors(
+    subreddit_id: int | None = None,
+    since: datetime | None = None,
+    until: datetime | None = None,
+    limit: int = Query(10, ge=1, le=50),
+    db: AsyncSession = Depends(get_db),
+):
+    return await analytics_service.get_top_authors(db, subreddit_id, since, until, limit)
+
+
+@router.get("/subreddit-summary")
+async def subreddit_summary(
+    since: datetime | None = None,
+    until: datetime | None = None,
+    db: AsyncSession = Depends(get_db),
+):
+    return await analytics_service.get_subreddit_summary(db, since, until)
+
+
+@router.get("/flair-distribution")
+async def flair_distribution(
+    subreddit_id: int = Query(...),
+    since: datetime | None = None,
+    until: datetime | None = None,
+    db: AsyncSession = Depends(get_db),
+):
+    return await analytics_service.get_flair_distribution(db, subreddit_id, since, until)