feat(tapo-agent): add schedule/countdown timer API support

- Fork tapo crate to add missing schedule/timer APIs
- Add get_countdown_rules, get_schedule_rules, get_next_event methods
- New readings: countdown_active, countdown_remain, schedule_count,
  schedule_active_count, next_event_time
- Add local compilation to build script alongside cross-compilation
- Implement offline polling - device collection continues when server disconnects
- Add more device readings: on_time, signal_level, rssi, runtime_today/month, energy_month

Vendored tapo fork in tapo-fork/ with minimal changes to add schedule APIs.

agents/tapo/tapo-fork/tapo-py/src/errors.rs

@@ -0,0 +1,23 @@
+use pyo3::PyErr;
+use pyo3::exceptions::PyException;
+use tapo::Error;
+
+pub struct ErrorWrapper(pub Error);
+
+impl From<Error> for ErrorWrapper {
+    fn from(err: Error) -> Self {
+        Self(err)
+    }
+}
+
+impl From<anyhow::Error> for ErrorWrapper {
+    fn from(err: anyhow::Error) -> Self {
+        Self(err.into())
+    }
+}
+
+impl From<ErrorWrapper> for PyErr {
+    fn from(err: ErrorWrapper) -> PyErr {
+        PyException::new_err(format!("{:?}", err.0))
+    }
+}