Initial commit: MeshCore Open Flutter client

Open-source Flutter client for MeshCore LoRa mesh networking devices.

Features:
- BLE device scanning and connection
- Nordic UART Service (NUS) integration
- Material 3 design with system theme support
- Provider-based state management
- Placeholder screens for chat, contacts, and settings

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

linux/flutter/generated_plugin_registrant.cc

@@ -0,0 +1,11 @@
+//
+//  Generated file. Do not edit.
+//
+
+// clang-format off
+
+#include "generated_plugin_registrant.h"
+
+
+void fl_register_plugins(FlPluginRegistry* registry) {
+}