fix(installer): prioritize user-installed packages over server-libs

Change sys.path.insert(0, ...) to sys.path.append(...) for server
site-packages so user-installed packages in system site-packages
take precedence over bundled server-libs packages.

Previously, server-libs were inserted at the front of sys.path,
causing bundled versions to override user-installed versions
(e.g., streamlit).

Author: mfranczel

installer/module/virtual_environment.py

@@ -97,7 +97,7 @@ def import_package_bundle(
                 # Write conditional import that checks environment variable
                 pth_content = (
                     f"import os, sys; "
-                    f"sys.path.insert(0, '{bundle_site_package_path}') "
+                    f"sys.path.append('{bundle_site_package_path}') "
                     f"if os.environ.get('{condition_env}', '').lower() == 'true' else None"
                 )
                 pth_file.write(pth_content + "\n")