Ticket #135 - Memory and ticket pattern analysis implementation: Added `researcher_reviewed_at` column to tickets and agent_memories tables with indexes. Created `list_memories` MCP tool for browsing memories with filters (memory_type, reviewed_before, sort_by, direction, limit). Created `mark_as_reviewed` MCP tool for bulk marking tickets/memories as reviewed. Updated `list_tickets` with `reviewed_before` filter supporting 'null' for unreviewed or ISO 8601 timestamp. Added tools to researcher role permissions in mcp_permissions.yml. All 86 tests passing. Researcher workflow: Fetch unreviewed items with `reviewed_before: "null"`, analyze, create proposals if needed, then `mark_as_reviewed` to clear the queue.