HACS compatibility and validation

✅ What's changed

• Added official HACS validation and Hassfest workflows
• Added the integration brand icon required for HACS inclusion
• Updated the integration manifest links and version to 0.1.9
• Declared the Home Assistant HTTP dependency and configuration schema
• Updated the custom integration localization structure
• Improved HACS installation documentation and added a My Home Assistant shortcut

🧪 Validation

• ✅ HACS Action
• ✅ Home Assistant Hassfest