Eliminate nested and N+1 relation reads #204

Delivered

• Relation endpoint kinds are loaded in one batch instead of one lookup per relation.
• Authorized task titles are loaded in one project-scoped batch.
• Authorized active memory titles are loaded in one visibility-filtered batch.
• Private, inaccessible, archived, expired, and unpublished memory targets remain hidden.
• Task targets remain hidden from users without task-project membership.
• ProjectItemService.Resolve disposes its lookup context before authorization services run.
• KnowledgeService.GetProjectMemory disposes its number lookup context before loading history.
• Relation ordering, provenance, and direction are preserved.
• Focused resolver, visibility, task-patch, and MCP contract tests pass: 4/4.
• Commit dabb48f deployed to Conderis.