Initial commit: MT firmware project

- BLE peripheral applications
- dr_piezo and bladder_patch projects

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

external/nano-pb/LICENSE.txt

@@ -0,0 +1,20 @@
+Copyright (c) 2011 Petteri Aimonen <jpa at nanopb.mail.kapsi.fi>
+
+This software is provided 'as-is', without any express or 
+implied warranty. In no event will the authors be held liable 
+for any damages arising from the use of this software.
+
+Permission is granted to anyone to use this software for any 
+purpose, including commercial applications, and to alter it and 
+redistribute it freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you 
+   must not claim that you wrote the original software. If you use 
+   this software in a product, an acknowledgment in the product 
+   documentation would be appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and 
+   must not be misrepresented as being the original software.
+
+3. This notice may not be removed or altered from any source 
+   distribution.