Add auxiliary monitor configuration and enhance trigger logic for KVM switching

app/config.py

@@ -18,13 +18,20 @@ SUPPORTED_TARGET_PORTS = {
 @dataclass(slots=True)
 class AppConfig:
     device_port: str = "DP1"
+    auxiliary_monitor_id: str | None = None
 
     @classmethod
     def from_dict(cls, data: dict[str, object]) -> "AppConfig":
-        return cls(device_port=_coerce_port_name(data.get("device_port"), "DP1"))
+        return cls(
+            device_port=_coerce_port_name(data.get("device_port"), "DP1"),
+            auxiliary_monitor_id=_coerce_aux_monitor_id(data.get("auxiliary_monitor_id")),
+        )
 
-    def to_dict(self) -> dict[str, str]:
-        return {"device_port": self.device_port}
+    def to_dict(self) -> dict[str, str | None]:
+        return {
+            "device_port": self.device_port,
+            "auxiliary_monitor_id": self.auxiliary_monitor_id,
+        }
 
     def validate(self) -> list[str]:
         errors: list[str] = []
@@ -43,7 +50,10 @@ class ConfigStore:
 
     def get(self) -> AppConfig:
         with self._lock:
-            return AppConfig(device_port=self._config.device_port)
+            return AppConfig(
+                device_port=self._config.device_port,
+                auxiliary_monitor_id=self._config.auxiliary_monitor_id,
+            )
 
     def save(self, config: AppConfig) -> AppConfig:
         errors = config.validate()
@@ -55,8 +65,14 @@ class ConfigStore:
                 json.dumps(config.to_dict(), indent=2),
                 encoding="utf-8",
             )
-            self._config = AppConfig(device_port=config.device_port)
-            return AppConfig(device_port=self._config.device_port)
+            self._config = AppConfig(
+                device_port=config.device_port,
+                auxiliary_monitor_id=config.auxiliary_monitor_id,
+            )
+            return AppConfig(
+                device_port=self._config.device_port,
+                auxiliary_monitor_id=self._config.auxiliary_monitor_id,
+            )
 
     def _load_from_disk(self) -> AppConfig:
         if not self.path.exists():
@@ -79,3 +95,11 @@ def _coerce_port_name(value: object, default: str) -> str:
         if normalized in SUPPORTED_TARGET_PORTS:
             return normalized
     return default
+
+
+def _coerce_aux_monitor_id(value: object) -> str | None:
+    if isinstance(value, str):
+        normalized = value.strip()
+        if normalized:
+            return normalized
+    return None