Clean release snapshot

.packages/README.md

@@ -0,0 +1,70 @@
+# Package lists
+
+System packages and Python dependencies required to build Slopsmith Desktop.
+
+## Files
+
+| File | Purpose |
+|---|---|
+| `apt.txt` | Ubuntu/Debian system packages (apt) |
+| `brew.txt` | macOS system packages (Homebrew) |
+| `choco.txt` | Windows system packages (Chocolatey) |
+| `python.txt` | Python packages (pip) - **shared across all platforms** |
+
+## Purpose
+
+Single source of truth for dependencies across:
+- **Local development** (via `.devcontainer/`)
+- **GitHub Actions CI** (`.github/workflows/build.yml`)
+- **Manual installation** by contributors
+
+## Usage
+
+### System packages
+
+For system packages, filter out comments and blank lines before piping:
+
+```bash
+# Ubuntu/Debian
+grep -v '^[[:space:]]*#' .packages/apt.txt | grep -v '^[[:space:]]*$' | xargs sudo apt-get install -y
+
+# macOS
+grep -v '^[[:space:]]*#' .packages/brew.txt | grep -v '^[[:space:]]*$' | xargs brew install
+
+# Windows (PowerShell)
+Get-Content .packages/choco.txt | Where-Object { $_ -notmatch '^\s*#' -and $_ -notmatch '^\s*$' } | ForEach-Object { choco install $_ -y }
+```
+
+### Python packages
+
+The `python.txt` file is used directly by pip during the bundle step:
+
+```bash
+pip install -r .packages/python.txt
+```
+
+This file is referenced from:
+- `scripts/build-windows.sh` (Windows)
+- `scripts/build-macos.sh` (macOS)
+- `scripts/bundle-python.sh` (Linux)
+
+## Format
+
+- One package per line
+- Lines starting with `#` are comments
+- Blank lines are ignored
+- Standard `pip install -r` format for `python.txt`
+
+## Updating
+
+### Adding system dependencies
+1. Add to the appropriate `.packages/*.txt` for each OS
+2. Update `.devcontainer/` if applicable
+3. Test locally
+
+### Adding Python dependencies
+1. Add to `.packages/python.txt` (one file for all platforms)
+2. Ensure the package is available on all platforms
+3. Test builds on all three platforms
+
+Changes affect both local builds and CI, so verify end-to-end before merging.