fix AI-20
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Enhanced file metadata with MIME type, blob ID, and file name across context and workspace, now visible in UI and API.
- Added workspace-level matching for files and documents with configurable thresholds and workspace scoping in search queries.
- Introduced a new error type and user-friendly messaging for global workspace context matching failures.
- **Bug Fixes**
- Improved consistent handling of file MIME types and nullable context IDs for accurate metadata.
- **Documentation**
- Updated GraphQL schema, queries, and mutations to include new metadata fields, optional parameters, and error types.
- **Style**
- Added new localization strings for global context matching error messages.
- **Tests**
- Extended test coverage with new and updated snapshot tests for metadata and matching logic.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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