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/lwip/src/FILES

@@ -0,0 +1,15 @@
+api/      - The code for the high-level wrapper API. Not needed if
+            you use the lowel-level call-back/raw API.
+
+apps/     - Higher layer applications that are specifically programmed
+            with the lwIP low-level raw API.
+
+core/     - The core of the TPC/IP stack; protocol implementations,
+            memory and buffer management, and the low-level raw API.
+
+include/  - lwIP include files.
+
+netif/    - Generic network interface device drivers are kept here.
+
+For more information on the various subdirectories, check the FILES
+file in each directory.