v0.6.0.0 — English default and language settings

AgentSCAD now defaults to English and lets you switch to Simplified Chinese in Settings → Language.

Added

• Immediate language switching across the workspace, settings, tooltips, notifications, and empty states.
• Saved browser preference, synchronization across tabs, and session-only switching when browser storage is blocked.
• Locale-aware dates and times.

Fixed

• Composer and unsaved provider drafts remain intact while switching languages and settings tabs.
• Both quick-start guides include cp .env.example .env before bun run db:push, addressing #18.

Validation

• 458 unit tests passed with web research disabled (AGENTSCAD_WEB_RESEARCH=off).
• TypeScript, ESLint, and the production build passed.
• Browser checks passed for persistence, draft retention, cross-tab synchronization, blocked storage, and layouts at 390, 1440, and 1728 pixels.