test(library-desk): add comprehensive entity linking tests
Add test suite covering:
- Entity mention detection (case-insensitive, whole-word matching, sorting)
- Content link addition (protection of existing links, longest-first matching)
- Integration tests (get entities with paths, create relationships, idempotency)
- Multi-tenancy isolation tests
All 17 tests passing. Validates entity linking functionality end-to-end.
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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
jpmschweitzerandClaude Opus 4.5
60b0100861