v0.9.3 - Architecture Consolidation

This release consolidates the settings architecture and enforces intent through structure.

Highlights:

• Settings ownership moved from schemas to tabs
• Tabs are the single source of truth for option keys and fields
• Global import/export via Tools tab
• Multisite scope is explicit and opt-in
• Directory structure realigned to architectural boundaries

Breaking changes:

• Schema-based settings layer removed
• SchemaContract and related abstractions removed

This release freezes the core architecture.