fix: installer stops the service reliably before upgrading and retries locked file copies; 1.1.5

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

installer/install_common.py

@@ -213,6 +213,16 @@ def stop_service() -> None:
     _sc(["stop", SERVICE_NAME])
 
 
+def ensure_service_stopped(timeout: float = 45.0) -> None:
+    """Stop the service and make sure its host process is really gone (an upgrade must be able
+    to overwrite the executable): SCM stop, wait, then kill any leftover host process."""
+    stop_service()
+    if not wait_service_state("STOPPED", timeout=timeout):
+        subprocess.run(["taskkill", "/F", "/IM", "GTIFiscalAgentService.exe"], capture_output=True, text=True)
+        wait_service_state("STOPPED", timeout=15)
+    time.sleep(2)
+
+
 def remove_service() -> None:
     """Stop then delete the service; both best effort (idempotent)."""
     stop_service()