Add devcontainer configuration for automatic bd setup

- Create .devcontainer/devcontainer.json with Go 1.23 environment
- Add setup.sh to build bd from source and install git hooks
- Add devcontainer README with documentation
- Update main README to mention devcontainer support
- Resolves bd-ry1u and GitHub issue #229

.devcontainer/README.md

@@ -0,0 +1,78 @@
+# beads Development Container
+
+This devcontainer configuration provides a fully-configured development environment for beads with:
+
+- Go 1.23 development environment
+- bd CLI built and installed from source
+- Git hooks automatically installed
+- All dependencies pre-installed
+
+## Quick Start
+
+### GitHub Codespaces
+
+1. Click the "Code" button on GitHub
+2. Select "Create codespace on main"
+3. Wait for the container to build (~2-3 minutes)
+4. The environment will be ready with bd installed and configured
+
+### VS Code Remote Containers
+
+1. Install the [Remote - Containers](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) extension
+2. Open the beads repository in VS Code
+3. Click "Reopen in Container" when prompted (or use Command Palette: "Remote-Containers: Reopen in Container")
+4. Wait for the container to build
+
+## What Gets Installed
+
+The `setup.sh` script automatically:
+
+1. Builds bd from source (`go build ./cmd/bd`)
+2. Installs bd to `/usr/local/bin/bd`
+3. Runs `bd init --quiet` (non-interactive initialization)
+4. Installs git hooks from `examples/git-hooks/`
+5. Downloads Go module dependencies
+
+## Verification
+
+After the container starts, verify everything works:
+
+```bash
+# Check bd is installed
+bd --version
+
+# Check for ready tasks
+bd ready
+
+# View project stats
+bd stats
+```
+
+## Git Configuration
+
+Your local `.gitconfig` is mounted into the container so your git identity is preserved. If you need to configure git:
+
+```bash
+git config --global user.name "Your Name"
+git config --global user.email "your.email@example.com"
+```
+
+## Troubleshooting
+
+**bd command not found:**
+- The setup script should install bd automatically
+- Manually run: `bash .devcontainer/setup.sh`
+
+**Git hooks not working:**
+- Check if hooks are installed: `ls -la .git/hooks/`
+- Manually install: `bash examples/git-hooks/install.sh`
+
+**Container fails to build:**
+- Check the container logs for specific errors
+- Ensure Docker/Podman is running and has sufficient resources
+- Try rebuilding: Command Palette → "Remote-Containers: Rebuild Container"
+
+## Related Issues
+
+- GitHub Issue [#229](https://github.com/steveyegge/beads/issues/229): Git hooks not available in devcontainers
+- bd-ry1u: Publish official devcontainer configuration