feat: v0.1.51 + G13/G14/G15 tests (126/126 PASS)

- fix: UpdateService IsInvalid → 400 (was 500 for ruby3.0 runtime)
- test: G13 edge cases — 40 tests, 40 PASS (name validation, boundary values,
  lifecycle, state transitions, update validation, upload edge cases)
- test: G14 cluster chaos — 20 tests, 20 PASS (self-healing, pod kill,
  OOM kill, kaniko interrupt, operator restart)
- test: G15 combined chaos — 21 tests, 21 PASS (CRUD under chaos, upload
  during self-heal, concurrent creates, errors after restart, rapid lifecycle)
- doc: progress.md, errors/log.md, decisions/log.md — полная документация сессии

internal/api/handler/services.go

@@ -232,6 +232,10 @@ func (h *Handler) UpdateService(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := h.K8s.Update(r.Context(), svc); err != nil {
+		if errors.IsInvalid(err) {
+			writeJSON(w, http.StatusBadRequest, errResp("invalid service spec: "+err.Error()))
+			return
+		}
 		writeJSON(w, http.StatusInternalServerError, errResp(err.Error()))
 		return
 	}