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/services/author_service.py

@@ -0,0 +1,79 @@
+from datetime import datetime
+from sqlalchemy import select, func
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from backend.models.author import Author
+from backend.models.post import Post
+from backend.models.comment import Comment
+
+
+async def list_authors(
+    db: AsyncSession,
+    subreddit_id: int | None = None,
+    sort_by: str = "total_comments",
+    sort_order: str = "desc",
+    since: datetime | None = None,
+    until: datetime | None = None,
+    page: int = 1,
+    per_page: int = 25,
+) -> tuple[list[dict], int]:
+    base = select(Author)
+
+    if subreddit_id or since or until:
+        # Need to compute activity counts with filters
+        post_count = (
+            select(func.count(Post.id))
+            .where(Post.author_id == Author.id)
+        )
+        comment_count = (
+            select(func.count(Comment.id))
+            .where(Comment.author_id == Author.id)
+        )
+
+        if subreddit_id:
+            post_count = post_count.where(Post.subreddit_id == subreddit_id)
+            comment_count = comment_count.join(Post).where(Post.subreddit_id == subreddit_id)
+        if since:
+            post_count = post_count.where(Post.created_utc >= since)
+            comment_count = comment_count.where(Comment.created_utc >= since)
+        if until:
+            post_count = post_count.where(Post.created_utc <= until)
+            comment_count = comment_count.where(Comment.created_utc <= until)
+
+        base = select(
+            Author,
+            post_count.correlate(Author).scalar_subquery().label("filtered_posts"),
+            comment_count.correlate(Author).scalar_subquery().label("filtered_comments"),
+        )
+    else:
+        base = select(Author)
+
+    count_stmt = select(func.count()).select_from(base.subquery())
+    total = (await db.execute(count_stmt)).scalar() or 0
+
+    sort_col = getattr(Author, sort_by, Author.total_comments)
+    if sort_order == "asc":
+        base = base.order_by(sort_col.asc())
+    else:
+        base = base.order_by(sort_col.desc())
+
+    base = base.offset((page - 1) * per_page).limit(per_page)
+
+    result = await db.execute(base)
+    authors = []
+    for row in result.all():
+        if isinstance(row, tuple):
+            author = row[0]
+        else:
+            author = row
+        data = {c.name: getattr(author, c.name) for c in author.__table__.columns}
+        authors.append(data)
+
+    return authors, total
+
+
+async def get_author(db: AsyncSession, author_id: int) -> dict | None:
+    author = await db.get(Author, author_id)
+    if not author:
+        return None
+    return {c.name: getattr(author, c.name) for c in author.__table__.columns}