FIX(app): restore su - ubuntu -c for proper env and PATH

- su ubuntu -c may not set env vars properly
- Change to su - ubuntu -c to use login shell environment
- Projects path is hardcoded to /home/ubuntu/Projects

services/backend/tools/bash_tool.py

@@ -91,16 +91,15 @@ def execute_host(command: str, timeout: int = 30, use_sudo: bool = False) -> str
         # -n: network namespace
         # -i: IPC namespace
         # Run as ubuntu user to avoid git "dubious ownership" errors
-        # Use 'su ubuntu -c' (without -) to preserve current directory context
-        # This allows commands to work from SSH initial directory
+        # Use 'su - ubuntu -c' to get proper environment variables and PATH
+        # Projects folder is at /home/ubuntu/Projects (hardcoded in prompts)
         if use_sudo:
             # For sudo commands, run directly with sudo
             nsenter_command = f"nsenter -t 1 -m -u -n -i -- sh -c {subprocess.list2cmdline([f'sudo {command}'])}"
         else:
-            # For regular commands, run as ubuntu user
-            # Use 'su ubuntu -c' (not 'su - ubuntu -c') to preserve current directory
-            # This matches SSH behavior where you start from the initial directory
-            nsenter_command = f"nsenter -t 1 -m -u -n -i -- su ubuntu -c {subprocess.list2cmdline([command])}"
+            # For regular commands, run as ubuntu user with login shell
+            # This ensures proper environment variables (PATH, HOME, etc.)
+            nsenter_command = f"nsenter -t 1 -m -u -n -i -- su - ubuntu -c {subprocess.list2cmdline([command])}"
 
         result = subprocess.run(
             nsenter_command,