v1.2.0: unified executor + flexible instance refs + params-render.js

Phase 1 — New modules:
- api/utils.py: find_uid(), uid_from_location() (replaces 2 duplicates)
- operations/poll.py: poll_until_done() (shared sync/async polling)
- operations/executor.py: execute_operation() (single CREATE/non-CREATE flow)

Phase 2 — Format + validation:
- routes/api_scenario_defs.py: _validate_steps with output/instance_ref/instance_uid
- operations/scenario.py: resolve instance_uid > instance_ref > service_id,
  use executor + poll_until_done, persist instance_bindings

Phase 3 — Migration:
- routes/api_test.py: create/non-create through executor, _finish_op through poll_until_done
- db/init_db.py: startup cleanup of stuck scenario_runs (>1h)

Phase 4 — UI shared module:
- static/js/params-render.js: renderParamRow, renderMapFixedRow, collectParams
- static/js/operations.js: use params-render.js (remove duplicates)
- templates/index.html: include params-render.js
- app.py: bump 1.1.57 → 1.2.0

site/templates/index.html

@@ -149,6 +149,7 @@ window.APP = {
 };
 </script>
 <script src="{{ url_for('static', filename='js/utils.js') }}"></script>
+<script src="{{ url_for('static', filename='js/params-render.js') }}"></script>
 <script src="{{ url_for('static', filename='js/instances.js') }}"></script>
 <script src="{{ url_for('static', filename='js/operations.js') }}"></script>
 <script src="{{ url_for('static', filename='js/history.js') }}"></script>