fix: pass env vars to systemd-run via --setenv (v0.3.5)

- Previous fix failed because systemd-run does not inherit env vars by default
- Added explicit --setenv flags for SKD_UPDATE_* variables
- Bumped version to 0.3.5

backend/update.py

@@ -199,30 +199,33 @@ def report_status(
 
 
 def _run_async(script_path: Path, settings: Settings) -> None:
-    env = os.environ.copy()
-    env["SKD_UPDATE_SERVICE_URL"] = settings.update_service_url
-    env["SKD_UPDATE_PROJECT_ID"] = settings.update_project_id
-    env["SKD_UPDATE_TOKEN"] = _get_fresh_token(settings)
-    env["SKD_UPDATE_STATUS_FILE"] = settings.update_status_file
-    env["SKD_UPDATE_LOG_FILE"] = settings.update_log_file
+    # Explicitly gather the env vars we need to pass
+    env_vars = {
+        "SKD_UPDATE_SERVICE_URL": settings.update_service_url,
+        "SKD_UPDATE_PROJECT_ID": settings.update_project_id,
+        "SKD_UPDATE_TOKEN": _get_fresh_token(settings),
+        "SKD_UPDATE_STATUS_FILE": settings.update_status_file,
+        "SKD_UPDATE_LOG_FILE": settings.update_log_file,
+    }
 
-    # Use systemd-run to detach the update process from the current service unit.
-    # This ensures the script survives 'systemctl stop skd'.
-    # We use --unit to give it a predictable name prefix (though unique suffix is added)
-    # and --scope (or --service) to create a new unit.
-    # Since we need root (and likely run as root), this should work.
-    # Note: --collect ensures garbage collection of the transient unit.
+    # Construct systemd-run command with --setenv for each variable
     cmd = [
         "systemd-run",
         "--unit=skd-update",
         "--collect",
         "--description=Safe Kiddo Update Process",
-        str(script_path),
     ]
+    
+    for key, val in env_vars.items():
+        if val:  # Only pass if not empty
+            cmd.append(f"--setenv={key}={val}")
+            
+    cmd.append(str(script_path))
 
+    # We don't pass 'env' parameter to Popen because systemd-run ignores it 
+    # for the target process (it only uses it for itself, but we use --setenv).
     subprocess.Popen(
         cmd,
-        env=env,
         cwd="/",
         stdout=subprocess.DEVNULL,
         stderr=subprocess.DEVNULL,