feat: Enhance inference management with device tracking and telemetry updates

app/telemetry/telemetry_collector.py

@@ -26,6 +26,9 @@ class TelemetrySnapshot:
     cpu_percent_core: float       # process CPU per single core — can exceed 100%
     memory_mb: float | None       # process private working set in MB
     timestamp: float              # time.perf_counter() when snapshot was taken
+    # Inference fields — None when inference is disabled / model not loaded
+    inference_device: str | None = None   # e.g. "cpu", "mps"
+    inference_time_ms: float | None = None  # rolling average of model() call time
 
 
 class TelemetryCollector(QObject):
@@ -69,6 +72,10 @@ class TelemetryCollector(QObject):
         self._process.cpu_percent()  # first call always returns 0.0; discard
         self._cpu_count: int = max(psutil.cpu_count(logical=True) or 1, 1)
 
+        # Inference stats (updated externally via set_inference_stats)
+        self._inference_device: str | None = None
+        self._inference_time_ms: float | None = None
+
         # periodic snapshot timer
         self._timer = QTimer(self)
         self._timer.setInterval(update_interval_ms)
@@ -85,6 +92,16 @@ class TelemetryCollector(QObject):
         """Record the FPS that was requested from the camera."""
         self._target_fps = fps
 
+    def set_inference_stats(self, device: str, avg_ms: float) -> None:
+        """Update inference device and average inference time (called from MainWindow)."""
+        self._inference_device: str | None = device
+        self._inference_time_ms: float | None = avg_ms
+
+    def clear_inference_stats(self) -> None:
+        """Clear inference stats when inference is disabled."""
+        self._inference_device = None
+        self._inference_time_ms = None
+
     # ------------------------------------------------------------------
     # Frame subscriber callback
     # ------------------------------------------------------------------
@@ -175,6 +192,12 @@ class TelemetryCollector(QObject):
             cpu_percent_core=round(cpu_core, 1),
             memory_mb=round(mem_mb, 1) if mem_mb is not None else None,
             timestamp=now,
+            inference_device=self._inference_device,
+            inference_time_ms=(
+                round(self._inference_time_ms, 1)
+                if self._inference_time_ms is not None
+                else None
+            ),
         )
 
     def _make_empty_snapshot(self) -> TelemetrySnapshot:
@@ -187,4 +210,6 @@ class TelemetryCollector(QObject):
             cpu_percent_core=0.0,
             memory_mb=None,
             timestamp=time.perf_counter(),
+            inference_device=None,
+            inference_time_ms=None,
         )