init, basic glogg clone

CROSS_COMPILE.md

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+# Cross-Compilation Guide
+
+Build Windows binaries from Linux using Docker-based cross-compilation.
+
+## Prerequisites
+
+1. **Install Docker**:
+   ```bash
+   # Ubuntu/Debian
+   sudo apt-get install docker.io
+   sudo usermod -aG docker $USER
+   # Log out and back in for group changes to take effect
+   ```
+
+2. **Verify Docker**:
+   ```bash
+   docker --version
+   ```
+
+## Quick Start
+
+### Option 1: Interactive Menu
+```bash
+./cross-compile.sh
+```
+
+Then select:
+- `1` - Linux native
+- `2` - Windows (MinGW)
+- `3` - Both platforms
+- `4` - Exit
+
+### Option 2: Command Line
+```bash
+./cross-compile.sh windows  # Windows (MinGW/GNU)
+./cross-compile.sh all      # All platforms
+./cross-compile.sh linux    # Linux native
+```
+
+### Option 3: Make
+```bash
+make cross-windows  # Build for Windows
+make cross-all      # Build for all platforms
+```
+
+## What Gets Built
+
+Binaries are created in the `dist/` directory:
+- `rlogg-linux-x86_64` - Linux binary
+- `rlogg-windows-x86_64.exe` - Windows binary (MinGW)
+
+## How It Works
+
+The `cross` tool:
+1. Automatically installs on first use
+2. Uses Docker to run cross-compilation in containers
+3. Provides complete toolchains for each target
+4. No need to install Windows SDK or MinGW manually
+
+## About Windows Cross-Compilation
+
+### Why MinGW/GNU Only?
+
+When cross-compiling from Linux to Windows, only the **GNU target** (`x86_64-pc-windows-gnu`) is supported:
+
+- **MinGW (GNU)** - Uses open-source MinGW toolchain
+  - ✅ Fully supported by `cross` from Linux
+  - ✅ Works great for most Windows applications
+  - ✅ Smaller binaries
+  - ✅ No runtime dependencies on Visual C++ redistributables
+
+- **MSVC** - Microsoft Visual C++ toolchain
+  - ❌ Not available for cross-compilation from Linux
+  - ❌ Requires proprietary Microsoft tools
+  - ❌ Can only be built on Windows or via Windows VM
+
+### Compatibility
+
+The MinGW binaries work on **all Windows systems** (Windows 7+) without requiring additional runtime installations. They're fully compatible with standard Windows applications.
+
+## Troubleshooting
+
+### Docker permission denied
+```bash
+sudo usermod -aG docker $USER
+# Log out and back in
+```
+
+### cross installation fails
+```bash
+# Install from source
+cargo install cross --git https://github.com/cross-rs/cross
+```
+
+### Build fails with linker errors
+The `cross` tool handles all linker configuration automatically. If you see linker errors, try:
+```bash
+# Clean and rebuild
+make clean
+./cross-compile.sh windows
+```
+
+### Very slow first build
+The first build downloads the Docker image (~1-2 GB) and compiles dependencies. Subsequent builds are much faster due to caching.
+
+## Alternative: Manual Cross-Compilation (Advanced)
+
+If you don't want to use Docker, you can manually set up cross-compilation:
+
+### For Windows from Linux
+```bash
+# Install MinGW
+sudo apt-get install mingw-w64
+
+# Add Rust target
+rustup target add x86_64-pc-windows-gnu
+
+# Configure cargo
+mkdir -p ~/.cargo
+cat >> ~/.cargo/config.toml << EOF
+[target.x86_64-pc-windows-gnu]
+linker = "x86_64-w64-mingw32-gcc"
+EOF
+
+# Build
+cargo build --release --target x86_64-pc-windows-gnu
+```
+
+**Note**: This only works for the GNU target, not MSVC.
+
+## Testing Windows Binaries on Linux
+
+Use Wine to test Windows binaries:
+```bash
+# Install Wine
+sudo apt-get install wine64
+
+# Run the Windows binary
+wine dist/rlogg-windows-x86_64-gnu.exe
+```
+
+## CI/CD Integration
+
+The GitHub Actions workflow automatically cross-compiles for all platforms. Just push to trigger builds:
+```bash
+git push origin master
+```
+
+Artifacts are available in the Actions tab.
+
+## Performance Considerations
+
+Cross-compilation is:
+- **Fast**: Similar speed to native compilation
+- **Cached**: Dependencies are cached in Docker volumes
+- **Isolated**: Doesn't affect your system
+
+Typical build times:
+- First build: 2-5 minutes (includes Docker image download)
+- Incremental builds: 30-60 seconds