Update button_controller.py

Summary

Optimize GPIO button polling interval

Problem

Aggressive polling at 100 Hz (10ms interval) unnecessarily high for human button presses, causing elevated CPU usage with no benefit to responsiveness.

Changes

Changed default poll_interval_seconds from 0.01 to 0.05 (100 Hz → 20 Hz)
Updated ButtonRuntimeConfig dataclass default
Updated fallback default in constructor

linux_voice_assistant/button_controller.py

@@ -40,7 +40,9 @@ class ButtonRuntimeConfig:
     enabled: bool
     pin: int
     long_press_seconds: float
-    poll_interval_seconds: float = 0.01  # 100 Hz polling
+    # CRITICAL FIX: Change default from 0.01s to 0.05s (100 Hz -> 20 Hz)
+    # 80% reduction in CPU usage for button monitoring
+    poll_interval_seconds: float = 0.05  # 20 Hz polling
 
 
 class ButtonController:
@@ -73,6 +75,9 @@ class ButtonController:
         self.event_bus = event_bus
         self.state = state
 
+        # CRITICAL FIX: Default poll_interval_seconds to 0.05 instead of 0.01
+        default_poll_interval = 0.05
+        
         self._cfg = ButtonRuntimeConfig(
             enabled=getattr(config, "enabled", False),
             pin=getattr(config, "pin", 17),
@@ -80,9 +85,7 @@ class ButtonController:
                 getattr(config, "long_press_seconds", 1.0)
             ),
             poll_interval_seconds=float(
-                getattr(config, "poll_interval_seconds", 0.01)
-                if hasattr(config, "poll_interval_seconds")
-                else 0.01
+                getattr(config, "poll_interval_seconds", default_poll_interval)
             ),
         )