test: add pytest verification suite and gitea ci workflow

src/agent.py

@@ -18,9 +18,10 @@ from .utils import clamp, draw_global_grid, image_to_data_url, utc_now_iso
 try:
     import pyautogui
 except Exception as import_exc:
-    raise RuntimeError(
-        "pyautogui is required. Install dependencies with: pip install pyautogui pillow"
-    ) from import_exc
+    pyautogui = None  # type: ignore[assignment]
+    _PYAUTOGUI_IMPORT_ERROR = import_exc
+else:
+    _PYAUTOGUI_IMPORT_ERROR = None
 
 
 SYSTEM_PROMPT = """
@@ -52,6 +53,12 @@ class ScreenJobAgent:
         cancel_event: threading.Event | None = None,
         event_callback: Callable[[dict[str, Any]], None] | None = None,
     ) -> None:
+        if pyautogui is None:
+            raise RuntimeError(
+                "pyautogui is required for agent execution. "
+                "Install dependencies and ensure GUI access. "
+                f"Import error: {_PYAUTOGUI_IMPORT_ERROR}"
+            )
         self.client = client
         self.logger = logger
         self.artifacts = artifacts
@@ -784,4 +791,3 @@ class ScreenJobAgent:
             usage=self.usage,
             error=result_text,
         )
-