Initial plugin setup (v0.0.1)

- Main plugin file with PHP 8.3+ and WordPress 6.0+ version checks
- Plugin singleton class with admin menu and settings pages
- License Manager integration with SecureLicenseClient
- License settings tab with validation and activation
- Admin CSS and JavaScript for license management
- Gitea CI/CD workflow for automated releases
- Documentation: README.md, PLAN.md, CHANGELOG.md, CLAUDE.md
- Composer dependencies: Twig 3.0, license client
- Git submodule for wc-licensed-product-client library

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

.editorconfig

@@ -0,0 +1,15 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+indent_size = 2