NodeWave v0.11.0

Codec2 for slow links.

Added

• Codec2 (modes 700C, 1300, 2400, 3200 bit/s) for voice messages, next to Opus. The sender picks the codec from the slowest link on the path (see 0.10.0) or always the thinnest one if Always low bandwidth is on; a 15 s clip is about 1.3 KB with 700C and 4.5 KB with 2400 against about 15 KB with Opus 8k. A phone needs no setting: it plays whatever codec the clip names.
• The Codec2 C sources (version 1.2.0, LGPL-2.1, compatible with the GPL-3.0) are in app/src/main/cpp/codec2 with their licence and a note on how they were taken, built into a small separate library libnodewave_codec2.so through the NDK and CMake (app/src/main/cpp). Checked on the Mi Note 10, Honor View 10 and Samsung A52: the four modes encode and decode with the same results as the upstream library on a computer, and a clip sent over Bluetooth with CODEC2 2400 from the Mi was delivered and played on the Samsung.

Changed

• Building the app now needs the NDK (27.2) and CMake 3.22.1 from the Android SDK; Android Studio offers to install them.

Debug-signed build for testing: it updates over the other NodeWave pre-releases. Not independently audited, see docs/SECURITY.md.