Reject non-standard truthy numeric expressions in filters and document the parser as a supported subset of standard CEL syntax.
- remove legacy filter rewrites
- support standard equality in tag exists predicates
- add regression coverage for accepted and rejected expressions
- Updated memo and reaction filtering logic to use a unified engine for compiling filter expressions into SQL statements.
- Removed redundant filter parsing and conversion code from ListMemoRelations, ListReactions, and ListAttachments methods.
- Introduced IDList and UIDList fields in FindMemo and FindReaction structs to support filtering by multiple IDs.
- Removed old filter test files for reactions and attachments, as the filtering logic has been centralized.
- Updated tests for memo filtering to reflect the new SQL statement compilation approach.
- Ensured that unsupported user filters return an error in ListUsers method.