feat: media_async + media_index modules, media_files table, tests

- media_async: thread-per-task async engine with primitives (sha256, sign, copy, uuid, file_size)
- media_index: media_files DB table with register_async for indexing chunks
- chat_msg: async media submission via register_async, simplified chat_msg_submit fields
- voice_recorder/attachment_sender: write single file (no chunk splitting on caller side)
- inputbar/messagelist: updated to new simplified submit interface
- test_media_async: 4-thread stress test (200K ops / 2 sec, 0 errors)
- test_media_index: 9 cases covering commit edge cases + async flow
- build: Makefile.am, CMakeLists.txt, utun_sources.cmake updated

tools/chatgui/src/mainwindow.cpp

@@ -217,11 +217,13 @@ void MainWindow::setupSoundFromConfig() {
             m_recorder->setCompressorEnabled(compEnabled != 0);
             if (m_recorder->compressor()) {
                 audio_compressor_config_t compCfg = {0};
-                compCfg.max_gain_db = (float)m_db->getUiStateInt("compressor_max_gain_db", 30);
-                compCfg.lookback_ms = m_db->getUiStateInt("compressor_lookback_ms", 200);
-                compCfg.lookahead_ms = m_db->getUiStateInt("compressor_lookahead_ms", 100);
-                compCfg.rise_rate_per_500ms = (float)m_db->getUiStateInt("compressor_rise_rate_tenths", 20) / 10.0f;
-                compCfg.target_level = powf(10.0f, (float)m_db->getUiStateInt("compressor_target_level_db", -12) / 20.0f);
+                compCfg.sample_rate = 48000;
+                compCfg.channels = 1;
+                compCfg.max_gain_db = (float)m_db->getUiStateInt("compressor_max_gain_db", 25);
+                compCfg.lookback_ms = 200;
+                compCfg.lookahead_ms = 100;
+                compCfg.rise_rate_per_sec = (float)m_db->getUiStateInt("compressor_rise_rate", 10);
+                compCfg.target_level = 1.0f;
                 audio_compressor_configure(m_recorder->compressor(), &compCfg);
             }
         }