refactor: restructure services and add image/pdf extraction utilities

- Add image_extractor, pdf_downloader, pi_client, trends services
- Add shared utils module
- Refactor summarizer, embedder, routes for cleaner separation
- Update tests to match new service structure

app/routes/compare.py

@@ -2,19 +2,14 @@
 
 from __future__ import annotations
 
-import logging
-
 from fastapi import APIRouter, Depends, HTTPException, Query, Request
-from fastapi.templating import Jinja2Templates
 from sqlalchemy.orm import Session, joinedload
 
 from app.database import get_db
 from app.models import Paper
-
-logger = logging.getLogger(__name__)
+from app.utils import templates
 
 router = APIRouter()
-templates = Jinja2Templates(directory="app/templates")
 
 
 @router.get("/compare")