improve: 增强说话动画幅度，更自然地模拟人类讲话

reachy_mini_ha_voice/animations/conversation_animations.json

@@ -26,14 +26,14 @@
       "frequency_hz": 0.5
     },
     "speaking": {
-      "description": "Speaking animation - lively nodding like talking",
-      "pitch_amplitude_rad": 0.08,
-      "yaw_amplitude_rad": 0.06,
-      "roll_amplitude_rad": 0.03,
-      "z_amplitude_m": 0.005,
-      "antenna_amplitude_rad": 0.4,
+      "description": "Speaking animation - lively head movements simulating human speech",
+      "pitch_amplitude_rad": 0.12,
+      "yaw_amplitude_rad": 0.10,
+      "roll_amplitude_rad": 0.05,
+      "z_amplitude_m": 0.008,
+      "antenna_amplitude_rad": 0.5,
       "antenna_move_name": "wiggle",
-      "frequency_hz": 1.5
+      "frequency_hz": 2.0
     },
     "happy": {
       "description": "Happy/positive response",