fix: conditional backend-only mode and robust health check with retries

frontend/app/page.tsx

@@ -102,11 +102,17 @@ export default function HomePage() {
       }
     }
 
-    async function init() {
+    async function init(retries = 3) {
       try {
         await healthCheck();
         setStatus("connected");
-      } catch {
+      } catch (e) {
+        console.error("Connection attempt failed", e);
+        if (retries > 0) {
+          setStatus("listening"); // Show trying state
+          setTimeout(() => init(retries - 1), 3000);
+          return;
+        }
         setStatus("offline");
       }
 

start.sh

@@ -1,14 +1,18 @@
 #!/bin/bash
-# Trigger build: 2026-05-07 08:42
+# Trigger build: 2026-05-07 08:49
 
-# Start Backend
-echo "Starting Backend..."
-cd /app/backend && uvicorn app.main:app --host 0.0.0.0 --port 8000 &
-
-# Start Frontend
-echo "Starting Frontend..."
-cd /app/frontend && npm run start -- -p 3000 &
-
-# Start Nginx
-echo "Starting Nginx..."
-nginx -g "daemon off;"
+if [ "$SERVICE_TYPE" = "backend" ]; then
+    echo "!!! STARTING IN BACKEND-ONLY MODE !!!"
+    cd /app/backend && uvicorn app.main:app --host 0.0.0.0 --port 7860
+else
+    echo "!!! STARTING IN FULL-STACK MODE !!!"
+    # Start Backend on internal port
+    cd /app/backend && uvicorn app.main:app --host 0.0.0.0 --port 8000 &
+    
+    # Start Frontend on internal port
+    cd /app/frontend && npm run start -- -p 3000 &
+    
+    # Start Nginx as the main entry point on HF port 7860
+    echo "Starting Nginx Proxy..."
+    nginx -g "daemon off;"
+fi