Add audio transcription with per-chat language support

Built over a weekend to read voice messages as text instead of listening.

Features:
- Alt-U to transcribe voice messages
- Alt-Shift-U to re-transcribe
- Alt-L to set language per chat
- 22+ languages (en, ru, uk, es, fr, de, zh, ja, etc.)
- Auto-truncate long transcriptions (configurable max lines)
- Works with OpenAI API, whisper.cpp, or local Whisper

Config in ~/.config/nchat/ui.conf:
- audio_transcribe_enabled=1  # turn it on
- audio_transcribe_language=auto  # or en, ru, uk, etc.
- audio_transcribe_max_lines=15  # truncate long ones

Database: Added transcriptionLanguage to chats2 table (schema v9)

Docs: TRANSCRIPTION.md for usage, TRANSCRIPTION-SETUP.md for setup

Author: bodharma

CMakeLists.txt

@@ -177,6 +177,8 @@ add_executable(nchat
   src/uilistborderview.h
   src/uilistdialog.cpp
   src/uilistdialog.h
+  src/uilanguagelistdialog.cpp
+  src/uilanguagelistdialog.h
   src/uilistview.cpp
   src/uilistview.h
   src/uimessagedialog.cpp
@@ -310,6 +312,9 @@ install(FILES src/nchat.1 DESTINATION "${CMAKE_INSTALL_MANDIR}/man1")
 configure_file(src/compose ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_INSTALL_LIBEXECDIR}/nchat/compose COPYONLY)
 install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_INSTALL_LIBEXECDIR}/nchat/compose DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}/nchat)
 
+configure_file(src/transcribe ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_INSTALL_LIBEXECDIR}/nchat/transcribe COPYONLY)
+install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_INSTALL_LIBEXECDIR}/nchat/transcribe DESTINATION ${CMAKE_INSTALL_LIBEXECDIR}/nchat)
+
 # Themes
 macro(add_theme themedir)
   configure_file(themes/${themedir}/color.conf ${CMAKE_CURRENT_BINARY_DIR}/share/nchat/themes/${themedir}/color.conf COPYONLY)

doc/TRANSCRIPTION-SETUP.md

@@ -0,0 +1,245 @@
+# Transcription Setup
+
+How to set up different transcription backends for nchat.
+
+## What You Need
+
+- nchat installed
+- Python 3.7+ (`python3 --version`)
+- pip (`pip3 --version`)
+
+---
+
+## Option 1: OpenAI API (Easiest)
+
+Fast (2-3 sec), accurate, easy. Costs $0.006/min. Audio goes to OpenAI.
+
+**Setup:**
+
+1. Get API key: https://platform.openai.com/api-keys
+
+2. Install packages:
+   ```bash
+   pip3 install openai requests
+   ```
+
+3. Set the key:
+   ```bash
+   export OPENAI_API_KEY='sk-...'
+   echo 'export OPENAI_API_KEY="sk-..."' >> ~/.bashrc
+   ```
+
+   macOS users also need:
+   ```bash
+   echo 'export OPENAI_API_KEY="sk-..."' >> ~/.zshenv
+   ```
+
+4. Configure nchat (`~/.config/nchat/ui.conf`):
+   ```conf
+   audio_transcribe_enabled=1
+   audio_transcribe_cache=1
+   ```
+
+5. Test:
+   ```bash
+   /usr/local/libexec/nchat/transcribe -f /path/to/test.ogg
+   ```
+
+Monitor costs at https://platform.openai.com/usage (set a budget limit!)
+
+---
+
+## Option 2: whisper.cpp (Local Server)
+
+Free, private, offline. Bit more setup. Fast with GPU.
+
+**Setup:**
+
+1. Install deps:
+   ```bash
+   # macOS
+   brew install ffmpeg cmake
+
+   # Linux
+   sudo apt install build-essential ffmpeg cmake git  # Debian/Ubuntu
+   sudo dnf install gcc-c++ ffmpeg cmake git          # Fedora
+   ```
+
+2. Build it:
+   ```bash
+   mkdir -p ~/whisper.cpp && cd ~/whisper.cpp
+   git clone https://github.com/ggerganov/whisper.cpp.git .
+   mkdir build && cd build
+   cmake .. -DWHISPER_BUILD_SERVER=ON
+   cmake --build . --config Release
+   ```
+
+3. Download a model:
+   ```bash
+   cd ~/whisper.cpp
+   bash ./models/download-ggml-model.sh base  # or tiny/small/medium/large
+   ```
+
+4. Start the server:
+   ```bash
+   cd ~/whisper.cpp
+   ./build/bin/server --model models/ggml-base.bin --host 127.0.0.1 --port 8080 --convert
+   ```
+
+   Run in background:
+   ```bash
+   nohup ./build/bin/server --model models/ggml-base.bin --host 127.0.0.1 --port 8080 --convert > server.log 2>&1 &
+   ```
+
+5. Install Python package:
+   ```bash
+   pip3 install requests
+   ```
+
+6. Configure nchat:
+   ```conf
+   audio_transcribe_enabled=1
+   audio_transcribe_command=/usr/local/libexec/nchat/transcribe -f '%1' -s whisper-cpp
+   audio_transcribe_cache=1
+   ```
+
+7. Test:
+   ```bash
+   curl http://localhost:8080/health
+   /usr/local/libexec/nchat/transcribe -f /path/to/test.ogg -s whisper-cpp
+   ```
+
+**Want auto-start on boot?** Set up a systemd service (Linux) or launchd (macOS) - Google it.
+
+---
+
+## Option 3: Whisper Python (Local)
+
+Free, private, simple. Slower than whisper.cpp, uses more RAM.
+
+**Setup:**
+
+1. Install ffmpeg:
+   ```bash
+   brew install ffmpeg  # macOS
+   sudo apt install ffmpeg python3-dev  # Debian/Ubuntu
+   sudo dnf install ffmpeg python3-devel  # Fedora
+   ```
+
+2. Install Whisper:
+   ```bash
+   pip3 install faster-whisper  # Faster (recommended)
+   # or
+   pip3 install openai-whisper  # Original (slower)
+   ```
+
+3. Configure nchat:
+   ```conf
+   audio_transcribe_enabled=1
+   audio_transcribe_command=/usr/local/libexec/nchat/transcribe -f '%1' -s whisper-local -m base
+   audio_transcribe_cache=1
+   ```
+
+4. Test:
+   ```bash
+   /usr/local/libexec/nchat/transcribe -f /path/to/test.ogg -s whisper-local
+   ```
+
+Models download automatically on first use. Pick a size: `tiny` (fast, meh), `base` (balanced), `small`/`medium`/`large` (slower, better).
+
+Got an NVIDIA GPU? Use `pip3 install faster-whisper[gpu]` after installing CUDA.
+
+---
+
+## Option 4: Groq API (Cheaper Alternative)
+
+Like OpenAI but cheaper ($0.001/min vs $0.006/min). Still fast.
+
+**Setup:**
+
+1. Get API key from https://console.groq.com/
+
+2. Install:
+   ```bash
+   pip3 install groq requests
+   ```
+
+3. Set key:
+   ```bash
+   export GROQ_API_KEY='gsk-...'
+   echo 'export GROQ_API_KEY="gsk-..."' >> ~/.bashrc
+   echo 'export GROQ_API_KEY="gsk-..."' >> ~/.zshenv  # macOS
+   ```
+
+4. You'll need to hack the transcribe script to add Groq support (it's not built-in yet). Or just use OpenAI.
+
+---
+
+## Testing
+
+After setup:
+
+```bash
+# Test the script
+/usr/local/libexec/nchat/transcribe -f /path/to/test.ogg
+
+# Check nchat config
+grep transcribe ~/.config/nchat/ui.conf
+```
+
+In nchat: Select a voice message, press `Alt-u`, see if it works.
+
+---
+
+## Troubleshooting
+
+**"Command not found"**
+```bash
+ls -l /usr/local/libexec/nchat/transcribe  # Check if it exists
+```
+
+**"No module named 'openai'"**
+```bash
+pip3 install openai  # or whatever package is missing
+```
+
+**"API key not set"**
+```bash
+echo $OPENAI_API_KEY  # Check it's set
+echo 'export OPENAI_API_KEY="sk-..."' >> ~/.bashrc
+echo 'export OPENAI_API_KEY="sk-..."' >> ~/.zshenv  # macOS
+```
+
+**whisper.cpp server not responding**
+```bash
+curl http://localhost:8080/health  # Check if running
+cd ~/whisper.cpp && ./build/bin/server --model models/ggml-base.bin --host 127.0.0.1 --port 8080 --convert
+```
+
+**Timeouts**
+```conf
+audio_transcribe_timeout=60  # Increase in ui.conf
+```
+
+**Need ffmpeg**
+```bash
+brew install ffmpeg  # macOS
+sudo apt install ffmpeg  # Linux
+```
+
+**High CPU/RAM**
+
+Use a smaller model (`-m tiny`), or switch to whisper.cpp, or just use the API.
+
+---
+
+## Quick Comparison
+
+| Option | Speed | Privacy | Cost | Setup |
+|--------|-------|---------|------|-------|
+| OpenAI | Fast | Low | $0.006/min | Easy |
+| whisper.cpp | Good | High | Free | Medium |
+| Whisper Python | OK | High | Free | Easy |
+| Groq | Fast | Low | $0.001/min | Easy |
+
+Pick what works for you.