fix(backend): serve React frontend from FastAPI

- Serve index.html on root /
- Mount /assets for React static files
- Backend now serves both frontend and API
- Works with simple ProxyPass config

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

backend/app/main.py

@@ -5,9 +5,11 @@ Main application entry point with CORS, middleware, and routers.
 
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
-from fastapi.responses import JSONResponse
+from fastapi.responses import JSONResponse, FileResponse
+from fastapi.staticfiles import StaticFiles
 from contextlib import asynccontextmanager
 import os
+from pathlib import Path
 
 from app.api import auth, files, metadata, templates
 from app.api import import_api
@@ -73,17 +75,26 @@ app.include_router(templates.router, prefix="/templates", tags=["templates"])
 app.include_router(import_api.router, prefix="/import", tags=["import"])
 
 
-# Root endpoint
+# Serve React frontend
+STATIC_DIR = Path("/var/www/html/solventum-image-metadata")
+
 @app.get("/")
 async def root():
-    """Root endpoint - API info"""
-    return {
-        "name": "Oliver Metadata Tool API",
-        "version": "4.0.0",
-        "status": "running",
-        "docs": "/docs",
-        "redoc": "/redoc"
-    }
+    """Serve React index.html or API info"""
+    if STATIC_DIR.exists() and (STATIC_DIR / "index.html").exists():
+        return FileResponse(str(STATIC_DIR / "index.html"))
+    else:
+        return {
+            "name": "Oliver Metadata Tool API",
+            "version": "4.0.0",
+            "status": "running",
+            "docs": "/docs",
+            "redoc": "/redoc"
+        }
+
+# Mount static files for React assets
+if STATIC_DIR.exists():
+    app.mount("/assets", StaticFiles(directory=str(STATIC_DIR / "assets")), name="assets")
 
 
 # Health check endpoint