Add licensed variable product support for duration-based licenses (v0.5.3)

Customers can now purchase licenses with different durations (monthly,
yearly, lifetime) through WooCommerce product variations. Each variation
can have its own license validity settings.

New features:
- LicensedVariableProduct class for variable licensed products
- LicensedProductVariation class for individual variations
- Per-variation license duration and max activations settings
- Duration labels in checkout (Monthly, Quarterly, Yearly, etc.)
- Full support for WooCommerce Blocks checkout with variations
- Updated translations for German (de_CH)

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

CLAUDE.md

@@ -32,10 +32,6 @@ This project is proudly **"vibe-coded"** using Claude.AI - the entire codebase w
 
 **Note for AI Assistants:** Clean this section after the specific features are done or new releases are made. Effective changes are tracked in `CHANGELOG.md`. Do not add completed versions here - document them in the Session History section at the end of this file.
 
-### Version 0.5.2
-
-*No planned bugfixes yet.*
-
 ### Version 0.6.0
 
 *No planned features yet.*
@@ -1341,3 +1337,44 @@ Security enhancement release adding per-license customer secrets for API respons
 - Created release package: `releases/wc-licensed-product-0.5.2.zip` (845 KB)
 - SHA256: `2d61a78ac5ba0f1d115a6401e6dded5b872b18f5530027c371604cbd18e9e27c`
 - Tagged as `v0.5.2` and pushed to `main` branch
+
+### 2026-01-26 - Version 0.5.3 - Variable Licensed Products
+
+**Overview:**
+
+Major feature release adding support for WooCommerce variable products. Customers can now purchase licenses with different durations (monthly, yearly, lifetime) as product variations.
+
+**New files:**
+
+- `src/Product/LicensedVariableProduct.php` - Variable product class extending `WC_Product_Variable`
+- `src/Product/LicensedProductVariation.php` - Variation class with license settings
+
+**Implemented:**
+
+- New `licensed-variable` product type for selling licenses with different durations
+- `LicensedVariableProduct` class extending WooCommerce variable products
+- `LicensedProductVariation` class for individual variation license settings
+- Variation-specific license duration fields in product edit page (days, max activations)
+- Duration labels (Monthly, Quarterly, Yearly, Lifetime) displayed in checkout
+- Variation ID tracking in order domain meta for proper license generation
+- WooCommerce Blocks checkout updated to handle variations with duration labels
+
+**Modified files:**
+
+- `src/Product/LicensedProductType.php` - Added licensed-variable type registration, variation hooks
+- `src/License/LicenseManager.php` - Added `isLicensedProduct()` helper, variation support in `generateLicense()`
+- `src/Plugin.php` - Updated license generation to handle variations
+- `src/Checkout/CheckoutController.php` - Variation support in domain field rendering
+- `src/Checkout/CheckoutBlocksIntegration.php` - Variation data in blocks checkout
+- `src/Checkout/StoreApiExtension.php` - Variation ID in Store API schema
+- `assets/js/checkout-blocks.js` - Variation handling in React components and DOM fallback
+
+**Technical notes:**
+
+- Variable product type shows in WooCommerce product type selector as "Licensed Variable Product"
+- Each variation can override parent's license duration and max activations
+- Variations are always virtual (licensed products don't ship)
+- `LicensedProductVariation::get_license_duration_label()` returns human-readable duration
+- Order meta `_licensed_product_domains` now includes optional `variation_id` field
+- License generation uses variation settings when `variation_id` is present in order item
+- Backward compatible: existing simple licensed products continue to work unchanged