feat(frontend): wire NatsTrigger editor to UserDraft

Same pattern as the Kafka trigger: persist getSaveCfg() on every edit,
overlay any local autosave on top of the backend value when openEdit
loads the trigger (with initialConfig/originalConfig snapshotted from
backend first so hasChanged correctly reports the overlay as unsaved),
drop the entry on successful update.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/triggers/nats/NatsTriggerEditorInner.svelte

@@ -23,6 +23,7 @@
 	import TriggerRetriesAndErrorHandler from '../TriggerRetriesAndErrorHandler.svelte'
 	import TriggerAdvancedBadges from '../TriggerAdvancedBadges.svelte'
 	import { deepEqual } from 'fast-equals'
+	import { UserDraft } from '$lib/userDraft.svelte'
 	import TriggerSuspendedJobsAlert from '../TriggerSuspendedJobsAlert.svelte'
 	import TriggerSuspendedJobsModal from '../TriggerSuspendedJobsModal.svelte'
 
@@ -132,16 +133,20 @@
 			edit = true
 			dirtyPath = false
 			await loadTrigger(defaultConfig)
+			if (!defaultConfig) {
+				initialConfig = structuredClone($state.snapshot(getSaveCfg()))
+			}
+			originalConfig = structuredClone($state.snapshot(getSaveCfg()))
+			const localCfg = UserDraft.get<Record<string, any>>('schedule_nats', ePath)
+			if (localCfg && !deepEqual(localCfg, getSaveCfg())) {
+				await loadTriggerConfig(localCfg)
+			}
 		} catch (err) {
 			sendUserToast(`Could not load nats trigger: ${err}`, true)
 		} finally {
 			clearTimeout(loadingTimeout)
 			drawerLoading = false
 			showLoading = false
-			if (!defaultConfig) {
-				initialConfig = structuredClone($state.snapshot(getSaveCfg()))
-			}
-			originalConfig = structuredClone($state.snapshot(getSaveCfg()))
 		}
 	}
 
@@ -248,6 +253,7 @@
 
 	async function updateTrigger(): Promise<void> {
 		deploymentLoading = true
+		const previousPath = initialPath
 		const cfg = natsConfig
 		const isSaved = await saveNatsTriggerFromCfg(
 			initialPath,
@@ -257,6 +263,7 @@
 			usedTriggerKinds
 		)
 		if (isSaved) {
+			UserDraft.remove('schedule_nats', previousPath)
 			onUpdate?.(cfg.path)
 			originalConfig = structuredClone($state.snapshot(getSaveCfg()))
 			initialPath = cfg.path
@@ -321,6 +328,11 @@
 		!drawerLoading &&
 			handleConfigChange(natsConfig, initialConfig, saveDisabled, edit, onConfigChange)
 	})
+
+	$effect(() => {
+		if (drawerLoading || !initialPath) return
+		UserDraft.save('schedule_nats', initialPath, natsConfig)
+	})
 </script>
 
 {#if mode === 'suspended'}