Implements async GATT notification buffering with D-Bus signal subscription.
Notifications are captured in circular buffers (100 values) and exposed via
dynamic MCP resources for polling or subscription.
New resources:
- bluetooth://ble/notifications (list active subscriptions)
- bluetooth://ble/{addr}/{uuid}/notifications (latest value + stats)
- bluetooth://ble/{addr}/{uuid}/notifications/history (buffered history)
New tools: bt_ble_notification_status, bt_ble_clear_notification_buffer
Updated bt_ble_notify to return resource URIs for easy access.
Ryan Malloy
766e8abfb4