Add 3-pin whistle sound sensor digital H/L detect on GPIO22.

Touch+LVGL UI shows QUIET/SOUND, pin level, hit count; no dB (digital only).

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -0,0 +1,13 @@
+.pio/
+.vscode/.browse.c_cpp.db*
+.vscode/c_cpp_properties.json
+.vscode/launch.json
+.vscode/ipch
+*.pyc
+__pycache__/
+.DS_Store
+Thumbs.db
+assets/
+*.elf
+# 构建目录里的 bin 不入库；firmware/ 预编译包要入库
+!firmware/**/*.bin