Add Pre-release Workflow with WASM File Uploads

[topheman]

Summary

Adds automatic pre-release creation with WASM files when git tags are pushed, enabling versioned plugin and repl-logic components.

Changes

• CI/CD: Added pre-release job to upload WASM files as GitHub release assets on git tags
• Optimization: Added duplicate action skipping to prevent redundant workflow runs
• Docs: Added CI section to README with usage examples
• Build: Enhanced justfile to include repl-logic-guest in plugin builds

Usage

pluginlab \
  --repl-logic https://github.com/topheman/webassembly-component-model-experiments/releases/download/pluginlab@0.4.1/repl_logic_guest.wasm \
  --plugins https://github.com/topheman/webassembly-component-model-experiments/releases/download/pluginlab@0.4.1/plugin_greet.wasm \
  # ... other plugins
  --allow-all

Testing

• ✅ CI workflows updated
• ✅ Documentation added
• ✅ Build system enhanced

No breaking changes - purely additive feature.