Initial implementation of WooCommerce Composable Products plugin

Implemented custom WooCommerce product type allowing customers to build their own
product bundles by selecting from predefined sets of products.

Features:
- Custom "Composable Product" type with admin interface
- Product selection by category, tag, or SKU
- Configurable selection limits (global and per-product)
- Dual pricing modes: fixed price or sum of selected products
- Modern responsive frontend with Twig templates
- AJAX add-to-cart functionality
- Full internationalization support (.pot file)
- WooCommerce settings integration
- Comprehensive documentation

Technical implementation:
- PHP 8.3+ with PSR-4 autoloading
- Twig 3.0 templating engine via Composer
- Vanilla JavaScript with jQuery for frontend interactions
- WordPress and WooCommerce hooks for seamless integration
- Security: input sanitization, validation, and output escaping
- Translation-ready with text domain 'wc-composable-product'

Documentation:
- README.md: Project overview and features
- INSTALL.md: Installation and usage guide
- IMPLEMENTATION.md: Technical architecture
- CHANGELOG.md: Version history

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

CLAUDE.md

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+# WooCommerce plugin for user composable products - AI Context Document
+
+**Author:** Marco Graetsch
+
+## Project Overview
+
+This plugin implements a special product type, for which users can select a limited number of product from a configurable set of simple or variable products. The limit of selectable products should be a global and per-product setting, for which global is the fallback. The set of selectable products can be defined per category, tag or SKU. The price is either a fixed price or the sum of the prices of the selected products. Think of a package of stickers as composable product, where each package can contain $limit number of stickers.
+
+### Key Fact: 100% AI-Generated
+
+This project is proudly **"vibe-coded"** using Claude.AI - the entire codebase was created through AI assistance.
+
+## Technical Stack
+
+- **Language:** PHP 8.3+
+- **Framework:** Latest WordPress Plugin API
+- **E-commerce:** WooCommerce 10.0+
+- **Template Engine:** Twig 3.0 (via Composer)
+- **Frontend:** Vanilla JavaScript + jQuery
+- **Styling:** Custom CSS
+- **Dependency Management:** Composer
+- **Internationalization:** WordPress i18n (.pot/.po/.mo files)
+
+## Implementation Details
+
+### Security Best Practices
+
+- All user inputs are sanitized (integers for quantities/prices)
+- Nonce verification on form submissions
+- Output escaping in templates (`esc_attr`, `esc_html`, `esc_js`)
+- Direct file access prevention via `ABSPATH` check
+
+### Translation Ready
+
+All user-facing strings use:
+
+```php
+__('Text to translate', 'wc-composable-product')
+_e('Text to translate', 'wc-composable-product')
+```
+
+Text domain: `wc-composable-product`
+
+**Available Translations (as of v1.1.22):**
+
+- `en_US` - English (United States)
+- `de_DE` - German (Germany, formal)
+- `de_DE_informal` - German (Germany, informal "du")
+- `de_CH` - German (Switzerland, formal "Sie")
+- `de_CH_informal` - German (Switzerland, informal "du")
+- `fr_CH` - French (Switzerland)
+- `it_CH` - Italian (Switzerland)
+
+Note: Swiss locales use CHF currency formatting in examples (e.g., "CHF 50.-")
+
+### Create releases
+
+**Important Notes**
+
+- The `vendor/` directory MUST be included in releases (Twig dependency required for runtime)
+- Running zip from wrong directory creates empty or malformed archives
+- Exclusion patterns must match the relative path structure used in zip command
+- Always verify the package with `unzip -l` and test extraction before committing
+- The `wp-core/` and `wp-plugins/` directories MUST NOT be included in releases!
+
+**Important Git Notes:**
+
+- Always commit from `dev` branch first
+- Tags should use format `vX.X.X` (e.g., `v1.1.22`)
+- Use annotated tags (`-a`) not lightweight tags
+- Commit messages should follow the established format with Claude Code attribution
+- `.claude/settings.local.json` changes are typically local-only (stash before rebasing)
+
+#### What Gets Released
+
+- All plugin source files
+- Compiled vendor dependencies
+- Translation files (.mo compiled from .po)
+- Assets (CSS, JS)
+- Documentation (README, CHANGELOG, etc.)
+
+#### What's Excluded
+
+- Git metadata (`.git/`)
+- Development files (`.vscode/`, `.claude/`, `CLAUDE.md`)
+- Logs and cache files
+- Previous releases
+- `composer.lock` (but `vendor/` is included)
+
+---
+
+Always refer to this document when starting work on this project. Good luck!