# Source Code Guidelines ## Error Handling - User-friendly and actionable messages - Proper error propagation ## Security - Sanitize HTML with DOMPurify - Validate trusted sources - Never log secrets ## State Management (Stores) - Follow domain-driven design for organizing files/folders - Clear public interfaces - Restrict extension access - Clean up subscriptions ## General Guidelines - Use `es-toolkit` for utility functions - Use TypeScript for type safety - Avoid `@ts-expect-error` - fix the underlying issue - Use `vue-i18n` for ALL user-facing strings (`src/locales/en/main.json`)