fix(spaces): bind app to port 7860 and disable SSR to fix HF launch timeout

- app_nemotron.py (HF app_file) defaulted to 7869 but HF health-checks 7860
- Prefer GRADIO_SERVER_PORT, then PORT, then 7860
- Disable Gradio SSR (Node proxy crashed, left :7860 unhealthy -> timeout)
- Apply same explicit 7860 + ssr_mode=False to app.py

app.py

@@ -678,4 +678,14 @@ if _webagent_dir.exists():
         print(f"[hearthnet] create_app patch failed: {_pe}")
 
 if __name__ == "__main__":
-    demo.launch()
+    import os
+
+    # HF Spaces health-checks port 7860. Bind explicitly and disable Gradio
+    # SSR mode (Node proxy on a different port crashes on HF and the health
+    # check on :7860 then times out -> "workload was not healthy").
+    _port = int(os.environ.get("GRADIO_SERVER_PORT", "7860"))
+    demo.launch(
+        server_name="0.0.0.0",
+        server_port=_port,
+        ssr_mode=False,
+    )

app_nemotron.py

@@ -525,9 +525,14 @@ Document Input ──► Nemotron Parse ──► Structured JSON
 
 if __name__ == "__main__":
     demo = build_app()
+    # HF Spaces health-checks port 7860. Prefer GRADIO_SERVER_PORT (set by HF),
+    # fall back to PORT, then 7860. Disable SSR: the Node proxy binds a different
+    # port and crashes on HF, leaving :7860 unhealthy -> launch timeout.
+    _port = int(os.getenv("GRADIO_SERVER_PORT") or os.getenv("PORT") or "7860")
     demo.launch(
         server_name="0.0.0.0",  # nosec B104
-        server_port=int(os.getenv("PORT", "7869")),
+        server_port=_port,
+        ssr_mode=False,
         theme=_theme,
         css="""
 .grad-banner { background: linear-gradient(135deg, #7c3aed 0%, #f97316 100%);