Problem: knowledge and learning operations were scattered across
httpapi and mcp handlers with no shared service layer. The hexagonal
refactor needs a single use-case service for both surfaces.
Change:
- app/knowledge.go: KnowledgeService (Search, Upsert, GetContent,
SoftDelete, Restore) and LearningService (ListPatterns,
UpsertPattern, Validate, Quarantine) wrapping the port interfaces.
- adapters/postgres/knowledge.go: KnowledgeRepo implements
KnowledgeRepository — Search, GetContent, Upsert, SoftDelete,
Restore with inline SQL matching the existing handler patterns
(full-text search ILIKE, upsert on conflict, soft-delete).
Verification: go build/vet, full test suite (18 pkgs), DB integration
(postgres + mcp — green).
