v1.1.55: split large files + CRUD scenario editor

Backend (5→7 files):
- api_test.py: 622→479, terraform functions → operations/terraform.py (142)
- api_scenario.py: 241→split into run (153) + defs (108) with _validate_steps()
- db/scenario_defs.py: +client_id, stand, is_seed in list_definitions

Frontend (1→10 files):
- app.js: 554→16 (loader), split into:
  utils.js (45), instances.js (89), operations.js (249),
  history.js (35), scenario-list.js (90)
- New CRUD: scenario-form.js (128), create (25), edit (12), delete (13)

Max file size: JS 249, PY 479

site/static/js/scenario-edit.js

@@ -0,0 +1,12 @@
+// scenario-edit.js — редактирование существующего сценария
+
+async function editScenario(defId) {
+    try {
+        const r = await fetch('/api/scenario/definitions/' + defId);
+        const def = await r.json();
+        if (def.error) { alert(def.error); return; }
+        showScenarioEditor(def);
+    } catch (e) {
+        alert('Ошибка загрузки: ' + e.message);
+    }
+}