- Added new section on schema file organization, detailing principles and decision criteria for merging or separating table files.
- Updated file naming conventions for single and multi-table files, as well as helper utilities.
- Refactored import paths in various schema files to use the new `_columnHelpers` module instead of the deprecated `columnHelpers`.
- Removed obsolete `customSql.ts`, `columnHelpers.ts`, `messageFts.ts`, `tag.ts`, `entityTag.ts`, and other related files to streamline the codebase.
This refactor improves clarity in database schema management and aligns file organization with best practices.
- Introduced a new method `runCustomMigrations` in `DbService` to execute custom SQL statements that Drizzle cannot manage, such as triggers and virtual tables.
- Updated `database-patterns.md` and `README.md` to document the handling of custom SQL and its importance in maintaining database integrity during migrations.
- Refactored `messageFts.ts` to define FTS5 virtual table and associated triggers as idempotent SQL statements for better migration management.
- Revised the README files for shared data and main data layers to improve clarity and structure.
- Consolidated documentation on shared data types and API types, removing the now-deleted `api-design-guidelines.md`.
- Streamlined directory structure descriptions and updated links to relevant documentation.
- Enhanced quick reference sections for better usability and understanding of the data architecture.
