feat: add plugin runtime and cross-device task orchestration

artemis/drivers/base.py

@@ -60,6 +60,7 @@ class ScreenData(BaseModel):
     height: int = Field(default=2400, description="Device screen height in pixels")
     timestamp: float = Field(default_factory=time.time, description="Capture timestamp")
     platform: str = Field(default="android", description="Platform identifier")
+    observation_text: str = ""
 
     model_config = ConfigDict(arbitrary_types_allowed=True)