feat: delete task/account, edit endpoint, richer event log

- store: DeleteAccount, DeleteTask, UpdateEndpoint (+ cascade/update tests)
- httpapi: DELETE /tasks/{id}, DELETE /tasks/{id}/accounts/{accountId},
  PUT /endpoints/{id}; delete guarded with 409 while task running
- orchestrator: enrich WS events with login/host/port/error (test + run + errors)
- web: delete buttons (task, account) with confirm, endpoint edit form,
  human-readable event log (source/dest, host:port, error text)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMHQTtnQtQqL8muAXHr9kd

internal/httpapi/endpoints.go

@@ -31,6 +31,29 @@ func (s *Server) handleCreateEndpoint(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, map[string]int64{"id": id})
 }
 
+func (s *Server) handleUpdateEndpoint(w http.ResponseWriter, r *http.Request) {
+	id, err := pathID(r, "id")
+	if err != nil {
+		http.Error(w, "bad id", http.StatusBadRequest)
+		return
+	}
+	var e store.Endpoint
+	if err := json.NewDecoder(r.Body).Decode(&e); err != nil {
+		http.Error(w, "bad json", http.StatusBadRequest)
+		return
+	}
+	if e.TLSMode != "ssl" && e.TLSMode != "starttls" && e.TLSMode != "plain" {
+		http.Error(w, "tls_mode must be ssl|starttls|plain", http.StatusBadRequest)
+		return
+	}
+	e.ID = id
+	if err := s.store.UpdateEndpoint(r.Context(), e); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
 func (s *Server) handleListEndpoints(w http.ResponseWriter, r *http.Request) {
 	eps, err := s.store.ListEndpoints(r.Context())
 	if err != nil {