Release 0.2.23

[ainyan03]

Audio

• Mic: record() never writes past the caller's buffer. The capture task used to emit a whole conversion step at a time, so lengths that were not a multiple of the step overran by a few bytes; record() with a length of 0 or a null pointer now returns false instead of reporting success. Queued recordings stay continuous whatever their length. (Mic: never write past the record() buffer; reject empty requests #370)
• Mic: record() called from the buffer release callback no longer fails while the publisher still holds the request lock; it waits a few ticks instead, so the "two buffers re-queued from the callback" pattern works. (Mic: let record() from the release callback wait briefly for the request lock #372)
• Speaker: play*() / stop() from an ordinary task and end() on another task are serialized under a request lock, closing a window in which the playback task handle could be used after end() had deleted the task. (Speaker: serialize request publish/notify with end() under a request lock #373)

Board fixes

• Core2 v1.1: setExtOutput(false) on USB power without a battery used to switch the PMIC off (DCDC under-voltage power-off, latched until the power key). The power-off is suspended for the transition, which turns it into an ESP32 brownout reset; the board reboots with the output enabled again. With a battery, or with 5 V on the bus, nothing changes. (Power: Core2 v1.1 suspend the DCDC under-voltage power-off while disabling the external output #375)
• Tab5: the IO expander leaves LCD_RST as an input with a pull-up instead of driving it, so the display reset stays with the display driver. (by @Ocean-lhy, Add support for ESP32P4: Capture LCD reset mode and update Power class #367)

Internal

• The library is built as a single translation unit: the .cpp files became .inl files included from M5Unified.cpp. Build times drop noticeably, and nothing changes for sketches or for builds through the Arduino / PlatformIO / ESP-IDF metadata. A custom build that globs *.cpp under src should list M5Unified.cpp only. (Build the library as a single translation unit #365)
• CI checks that the single translation unit sources stay consistent. (CI: check the single translation unit sources #366)
• Fix unused-function / unused-variable warnings on non-P4 targets (GCC 8, ESP-IDF 5.1); no behaviour change. (Fix unused-function/variable warnings on non-P4 targets #376)
• Require M5GFX 0.2.30 (ILI9342E detection, single translation unit build).