feat: add debug page with tables and logs viewer (Step 1)

Backend:
- Add /debug/tables endpoint to dump SQLite tables
- Add /debug/logs endpoint to read scrap.log

Frontend:
- Add react-router-dom for navigation
- Create HomePage and DebugPage components
- Add navigation bar with Debug link
- Style debug page with Gruvbox theme
- Fix package.json dependencies versions

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/main.py

@@ -5,7 +5,7 @@ from os import getenv
 from fastapi import FastAPI
 from dotenv import load_dotenv
 
-from backend.app.api import routes_config, routes_products, routes_scrape
+from backend.app.api import routes_config, routes_debug, routes_products, routes_scrape
 from backend.app.core.logging import logger
 from backend.app.core.scheduler import start_scheduler
 from backend.app.db.database import Base, engine
@@ -17,6 +17,7 @@ app = FastAPI(title="suivi_produit")
 app.include_router(routes_products.router)
 app.include_router(routes_scrape.router)
 app.include_router(routes_config.router)
+app.include_router(routes_debug.router)
 
 
 @app.on_event("startup")