feat(scenarios): add timeoutSeconds to scenarios and steps

- add timeoutSeconds field to scenario and step entities
- add timeoutSeconds to create/update DTOs for scenario and step
- enforce timeout via scheduler: abort run if step exceeds limit
- expose timeoutSeconds in MCP create/update scenario and step tools
- add client-side type, API, i18n, and form support for timeoutSeconds
- add integration tests for timeout persistence via REST and MCP

client/src/i18n/locales/en.json

@@ -185,6 +185,9 @@
     "export_modal_title": "Export Scenario",
     "export_include_environment": "Include Environment",
     "export_include_credentials": "Include Credentials",
+    "form_timeout": "Scenario Timeout (seconds)",
+    "form_timeout_placeholder": "Default: 600",
+    "form_timeout_hint": "Max seconds for the entire scenario run (default: 600)",
     "field_name": "Name",
     "field_id": "ID"
   },
@@ -222,7 +225,10 @@
     "form_session_placeholder": "e.g. my-session",
     "form_session_required": "Session name is required",
     "form_exec_code": "Exec code",
-    "form_exec_code_placeholder": "return await page.title();"
+    "form_exec_code_placeholder": "return await page.title();",
+    "form_timeout": "Step Timeout (seconds)",
+    "form_timeout_placeholder": "Default: 60",
+    "form_timeout_hint": "Max seconds for this step (default: 60)"
   },
   "runs": {
     "title": "Runs",