feat(immich): per-album scheduled/memory dispatch + template tooling

Dispatch: honor {kind}_collection_mode on TrackingConfig — "per_collection"
fans out one event per album; "combined" pools assets as before. Extract
build_immich_dispatch_events shared by cron and test paths.

Assets: collect_scheduled_assets attaches album_name/album_url/album_public_url
to each asset so combined-mode templates can attribute rows to their source
album. Default scheduled_assets templates render a multi-album header with
inline album list and per-row album link; memory_mode follows the same pattern.

UI: "Reset to default" buttons on notification and command template slots
(per-slot and whole-template), backed by new GET /*-template-configs/defaults
endpoints. tracking-configs "Preview template" now opens an inline preview
modal with locale tabs instead of navigating away; Edit button deep-links
with ?edit_slot=<name> so the destination auto-opens the config and scrolls
to the slot. Reset confirmations use ConfirmModal instead of window.confirm.

Fixes:
* NotificationDispatcher._session_ctx infinite recursion when no shared
  aiohttp.ClientSession was passed — broke test dispatch for periodic/
  scheduled/memory (cron path was unaffected).
* telegram-bots /chats/{id}/test now resolves chat.language_override /
  language_code instead of using the raw ?locale query param, matching
  the resolution the tracker-target test endpoint already used.
* scheduled_assets default template no longer emits a blank line between
  header and the first asset when the multi-album branch is taken.

frontend/src/routes/command-template-configs/+page.svelte

@@ -54,6 +54,11 @@
 	let editing = $state<number | null>(null);
 	let error = $state('');
 	let confirmDelete = $state<{ id: number; onconfirm: () => Promise<void> } | null>(null);
+	let confirmReset = $state<{
+		kind: 'slot' | 'all';
+		slotKey?: string;
+		message: string;
+	} | null>(null);
 	let slotPreview = $state<Record<string, string>>({});
 	let slotErrors = $state<Record<string, string>>({});
 	let slotErrorLines = $state<Record<string, number | null>>({});
@@ -253,6 +258,58 @@
 		}
 	}
 
+	function resetSlotToDefault(slotKey: string) {
+		if (!form.provider_type) return;
+		confirmReset = {
+			kind: 'slot',
+			slotKey,
+			message: t('templateConfig.resetSlotConfirm').replace('{locale}', activeLocale.toUpperCase()),
+		};
+	}
+
+	function resetAllToDefaults() {
+		if (!form.provider_type) return;
+		confirmReset = {
+			kind: 'all',
+			message: t('templateConfig.resetAllConfirm').replace(/\{locale\}/g, activeLocale.toUpperCase()),
+		};
+	}
+
+	async function performReset() {
+		if (!confirmReset || !form.provider_type) return;
+		const { kind, slotKey } = confirmReset;
+		confirmReset = null;
+		try {
+			if (kind === 'slot' && slotKey) {
+				const res = await api<Record<string, Record<string, string>>>(
+					`/command-template-configs/defaults?provider_type=${encodeURIComponent(form.provider_type)}&slot_name=${encodeURIComponent(slotKey)}&locale=${encodeURIComponent(activeLocale)}`,
+				);
+				const text = res?.[slotKey]?.[activeLocale];
+				if (!text) {
+					snackError(t('templateConfig.resetNoDefault'));
+					return;
+				}
+				setSlotValue(slotKey, text);
+				validateSlot(slotKey, text, true);
+			} else {
+				const res = await api<Record<string, Record<string, string>>>(
+					`/command-template-configs/defaults?provider_type=${encodeURIComponent(form.provider_type)}&locale=${encodeURIComponent(activeLocale)}`,
+				);
+				const nextSlots = { ...form.slots };
+				for (const [key, localeMap] of Object.entries(res || {})) {
+					const text = localeMap?.[activeLocale];
+					if (text === undefined) continue;
+					nextSlots[key] = { ...(nextSlots[key] || {}), [activeLocale]: text };
+				}
+				form.slots = nextSlots;
+				refreshAllPreviews();
+			}
+			snackSuccess(t('templateConfig.resetApplied'));
+		} catch (err: any) {
+			snackError(err.message);
+		}
+	}
+
 	function clone(c: CmdTemplateConfig) {
 		const slotsCopy: Record<string, Record<string, string>> = {};
 		for (const [k, v] of Object.entries(c.slots)) {
@@ -343,7 +400,7 @@
 			<p class="text-xs text-[var(--color-muted-foreground)] mb-2">{t('cmdTemplateConfig.commandResponsesHint')}</p>
 
 			<!-- Locale tabs -->
-			<div class="flex gap-1 mb-3 border-b border-[var(--color-border)]">
+			<div class="flex items-center gap-1 mb-3 border-b border-[var(--color-border)]">
 				{#each LOCALES as loc}
 					<button type="button"
 						class="px-3 py-1.5 text-xs font-medium rounded-t-md transition-colors {activeLocale === loc ? 'bg-[var(--color-primary)] text-[var(--color-primary-foreground)]' : 'text-[var(--color-muted-foreground)] hover:bg-[var(--color-muted)]'}"
@@ -351,6 +408,14 @@
 						{loc.toUpperCase()}
 					</button>
 				{/each}
+				{#if form.provider_type}
+					<button type="button" onclick={resetAllToDefaults}
+						title={t('templateConfig.resetAllToDefaults')}
+						class="ml-auto flex items-center gap-1 text-xs px-2 py-1 rounded-md border border-[var(--color-border)] text-[var(--color-muted-foreground)] hover:bg-[var(--color-muted)]">
+						<MdiIcon name="mdiRefresh" size={12} />
+						{t('templateConfig.resetAllToDefaults')}
+					</button>
+				{/if}
 			</div>
 
 			<!-- Slot filter -->
@@ -381,6 +446,11 @@
 								<button type="button" onclick={() => showVarsFor = slot.name}
 									class="text-xs text-[var(--color-muted-foreground)] hover:underline">{t('templateConfig.variables')}</button>
 							{/if}
+							<button type="button" onclick={() => resetSlotToDefault(slot.name)}
+								title={t('templateConfig.resetToDefault')}
+								class="text-xs text-[var(--color-muted-foreground)] hover:underline">
+								{t('templateConfig.resetToDefault')}
+							</button>
 						</div>
 
 						{#if showPreviewFor.has(slot.name) && slotPreview[slot.name] && !slotErrors[slot.name]}
@@ -472,6 +542,14 @@
 <ConfirmModal open={confirmDelete !== null} message={t('cmdTemplateConfig.confirmDelete')}
 	onconfirm={() => confirmDelete?.onconfirm()} oncancel={() => confirmDelete = null} />
 
+<ConfirmModal open={confirmReset !== null}
+	title={t('templateConfig.resetToDefault')}
+	message={confirmReset?.message || ''}
+	confirmLabel={confirmReset?.kind === 'all' ? t('templateConfig.resetAllToDefaults') : t('templateConfig.resetToDefault')}
+	confirmIcon="mdiRefresh"
+	onconfirm={performReset}
+	oncancel={() => confirmReset = null} />
+
 <BlockedByModal open={!!blockedBy} detail={blockedBy} onclose={() => blockedBy = null} />
 
 <!-- Variables reference modal -->

frontend/src/routes/notification-trackers/+page.svelte

@@ -84,17 +84,23 @@
 	let testMenuStyle = $state('');
 
 	// Test types: basic is always available; periodic/scheduled/memory only for providers
-	// that have those notification slots in their capabilities
-	const allTestTypes: Record<string, { key: string; icon: string; labelKey: string; requiredSlot?: string }> = {
+	// that have those notification slots in their capabilities AND have the feature
+	// enabled on the tracker's default TrackingConfig. A disabled feature on the
+	// default config means cron dispatch won't fire it in production either — so
+	// the test button would just surface a silent skip.
+	const allTestTypes: Record<string, {
+		key: string; icon: string; labelKey: string;
+		requiredSlot?: string; enabledField?: string;
+	}> = {
 		basic: { key: 'basic', icon: 'mdiSend', labelKey: 'notificationTracker.testBasic' },
-		periodic: { key: 'periodic', icon: 'mdiCalendarClock', labelKey: 'notificationTracker.testPeriodic', requiredSlot: 'periodic_summary_message' },
-		scheduled: { key: 'scheduled', icon: 'mdiCalendarCheck', labelKey: 'notificationTracker.testScheduled', requiredSlot: 'scheduled_assets_message' },
-		memory: { key: 'memory', icon: 'mdiHistory', labelKey: 'notificationTracker.testMemory', requiredSlot: 'memory_mode_message' },
+		periodic: { key: 'periodic', icon: 'mdiCalendarClock', labelKey: 'notificationTracker.testPeriodic', requiredSlot: 'periodic_summary_message', enabledField: 'periodic_enabled' },
+		scheduled: { key: 'scheduled', icon: 'mdiCalendarCheck', labelKey: 'notificationTracker.testScheduled', requiredSlot: 'scheduled_assets_message', enabledField: 'scheduled_enabled' },
+		memory: { key: 'memory', icon: 'mdiHistory', labelKey: 'notificationTracker.testMemory', requiredSlot: 'memory_mode_message', enabledField: 'memory_enabled' },
 	};
 
 	let testMenuTrackerId = $state<number | null>(null);
 	let testTypes = $derived.by(() => {
-		const base = [allTestTypes.basic];
+		const base: { key: string; icon: string; labelKey: string; disabledReason?: string }[] = [allTestTypes.basic];
 		if (!testMenuTrackerId) return base;
 		const tracker = notificationTrackers.find(t => t.id === testMenuTrackerId);
 		if (!tracker) return base;
@@ -103,8 +109,18 @@
 		const caps = allCapabilities[provider.type];
 		if (!caps) return base;
 		const slotNames = new Set((caps.notification_slots || []).map((s: any) => s.name));
+		const defaultTc = trackingConfigs.find(c => c.id === tracker.default_tracking_config_id);
 		for (const tt of [allTestTypes.periodic, allTestTypes.scheduled, allTestTypes.memory]) {
-			if (tt.requiredSlot && slotNames.has(tt.requiredSlot)) base.push(tt);
+			if (!tt.requiredSlot || !slotNames.has(tt.requiredSlot)) continue;
+			const enabled = !!defaultTc && !!tt.enabledField && !!(defaultTc as any)[tt.enabledField];
+			base.push({
+				key: tt.key, icon: tt.icon, labelKey: tt.labelKey,
+				// When surfaced, the button still renders but is disabled and
+				// shows *why* — users who land here via the test menu without
+				// having toggled the feature on Tracking Config see a clear
+				// pointer to the missing setting instead of a silent failure.
+				disabledReason: enabled ? undefined : 'notificationTracker.testDisabledHint',
+			});
 		}
 		return base;
 	});
@@ -516,6 +532,15 @@
 	onclose={() => { linkWarning = null; }}
 	onautoCreate={autoCreateLinks}
 	ondismiss={dismissLinkWarning}
+	onupdate={(remaining) => {
+		if (!linkWarning) return;
+		if (remaining.length === 0) {
+			linkWarning = null;
+			doSave();
+		} else {
+			linkWarning = { ...linkWarning, albums: remaining };
+		}
+	}}
 />
 
 <ConfirmModal

frontend/src/routes/notification-trackers/SharedLinkModal.svelte

@@ -1,17 +1,50 @@
 <script lang="ts">
 	import { t } from '$lib/i18n';
+	import { api } from '$lib/api';
+	import { snackError, snackSuccess } from '$lib/stores/snackbar.svelte';
 	import Modal from '$lib/components/Modal.svelte';
 	import MdiIcon from '$lib/components/MdiIcon.svelte';
 
+	interface AlbumIssue { id: string; name: string; issue: string }
+
 	interface Props {
-		linkWarning: { albums: any[]; providerId: number } | null;
+		linkWarning: { albums: AlbumIssue[]; providerId: number } | null;
 		linkCreating: boolean;
 		onclose: () => void;
 		onautoCreate: () => void;
 		ondismiss: () => void;
+		/** Called with the updated warning list after a per-row replace. */
+		onupdate?: (albums: AlbumIssue[]) => void;
 	}
 
-	let { linkWarning, linkCreating, onclose, onautoCreate, ondismiss }: Props = $props();
+	let { linkWarning, linkCreating, onclose, onautoCreate, ondismiss, onupdate }: Props = $props();
+
+	/** Per-row loading state for the "Replace" button. */
+	let replacing = $state<Record<string, boolean>>({});
+
+	/**
+	 * Expired and password-protected links can't be repaired in place — the
+	 * Immich API has no "reset" endpoint. The only remedy is to recreate the
+	 * link (which the backend does by POSTing a new one and returning it).
+	 * We surface the action per-row so users don't have to leave the form.
+	 */
+	async function replaceOne(album: AlbumIssue) {
+		if (!linkWarning) return;
+		replacing = { ...replacing, [album.id]: true };
+		try {
+			await api(`/providers/${linkWarning.providerId}/albums/${album.id}/shared-links`, {
+				method: 'POST',
+				body: JSON.stringify({ replace: true }),
+			});
+			snackSuccess(t('notificationTracker.createdLinks').replace('{count}', '1'));
+			const remaining = linkWarning.albums.filter(a => a.id !== album.id);
+			if (onupdate) onupdate(remaining);
+		} catch (err: any) {
+			snackError(t('notificationTracker.linkReplaceFailed').replace('{name}', album.name) + ': ' + err.message);
+		} finally {
+			replacing = { ...replacing, [album.id]: false };
+		}
+	}
 </script>
 
 <Modal open={linkWarning !== null} title={t('notificationTracker.missingLinksTitle')} onclose={onclose}>
@@ -19,13 +52,26 @@
 		<p class="text-sm mb-3" style="color: var(--color-muted-foreground);">
 			{t('notificationTracker.missingLinksDesc')}
 		</p>
-		<div class="space-y-1.5 mb-4 max-h-40 overflow-y-auto">
+		<div class="space-y-1.5 mb-4 max-h-60 overflow-y-auto">
 			{#each linkWarning.albums as album}
-				<div class="flex items-center justify-between text-sm px-2 py-1.5 rounded bg-[var(--color-muted)]/30">
-					<span class="font-medium">{album.name}</span>
-					<span class="text-xs px-1.5 py-0.5 rounded {album.issue === 'expired' ? 'bg-[var(--color-error-bg)] text-[var(--color-error-fg)]' : album.issue === 'password-protected' ? 'bg-[var(--color-warning-bg)] text-[var(--color-warning-fg)]' : 'bg-[var(--color-muted)] text-[var(--color-muted-foreground)]'}">
+				<div class="flex items-center justify-between gap-2 text-sm px-2 py-1.5 rounded bg-[var(--color-muted)]/30">
+					<div class="flex-1 min-w-0">
+						<span class="font-medium truncate block">{album.name}</span>
+						{#if album.issue === 'password-protected'}
+							<span class="text-[10px] block" style="color: var(--color-muted-foreground);">
+								{t('notificationTracker.linkPasswordProtectedNote')}
+							</span>
+						{/if}
+					</div>
+					<span class="text-xs px-1.5 py-0.5 rounded shrink-0 {album.issue === 'expired' ? 'bg-[var(--color-error-bg)] text-[var(--color-error-fg)]' : album.issue === 'password-protected' ? 'bg-[var(--color-warning-bg)] text-[var(--color-warning-fg)]' : 'bg-[var(--color-muted)] text-[var(--color-muted-foreground)]'}">
 						{album.issue === 'expired' ? t('notificationTracker.expired') : album.issue === 'password-protected' ? t('notificationTracker.passwordProtected') : t('notificationTracker.noLink')}
 					</span>
+					{#if album.issue === 'expired' || album.issue === 'password-protected'}
+						<button type="button" onclick={() => replaceOne(album)} disabled={replacing[album.id]}
+							class="text-xs px-2 py-1 rounded border border-[var(--color-border)] hover:bg-[var(--color-muted)] disabled:opacity-50 shrink-0">
+							{replacing[album.id] ? t('notificationTracker.linkReplacing') : t('notificationTracker.linkReplace')}
+						</button>
+					{/if}
 				</div>
 			{/each}
 		</div>

frontend/src/routes/notification-trackers/TestMenu.svelte

@@ -6,7 +6,13 @@
 		testMenuOpen: string | null;
 		testMenuStyle: string;
 		ttTesting: Record<string, string>;
-		testTypes: { key: string; icon: string; labelKey: string }[];
+		/**
+		 * When `disabledReason` is set, the button is rendered greyed out with a
+		 * tooltip pointing the user at the missing setting (e.g. "Enable Periodic
+		 * Summary in Tracking Config first"). Clicking is blocked — clicking an
+		 * unconfigured test would have surfaced as a silent server-side skip.
+		 */
+		testTypes: { key: string; icon: string; labelKey: string; disabledReason?: string }[];
 		ontest: (ttId: number, testType: string) => void;
 		onclose: () => void;
 	}
@@ -20,18 +26,27 @@
 		onclick={onclose}
 		onkeydown={(e) => { if (e.key === 'Escape') onclose(); }}>
 	</div>
-	<div style="{testMenuStyle} background:var(--color-card); border:1px solid var(--color-border); border-radius:0.5rem; box-shadow:0 10px 25px rgba(0,0,0,0.3); padding:0.25rem; min-width:10rem;">
+	<div style="{testMenuStyle} background:var(--color-card); border:1px solid var(--color-border); border-radius:0.5rem; box-shadow:0 10px 25px rgba(0,0,0,0.3); padding:0.25rem; min-width:12rem;">
 		{#each testTypes as tt}
+			{@const busy = !!ttTesting[`${testMenuOpen}_${tt.key}`]}
+			{@const blocked = !!tt.disabledReason}
 			<button
-				onclick={() => ontest(Number(testMenuOpen), tt.key)}
-				disabled={!!ttTesting[`${testMenuOpen}_${tt.key}`]}
+				onclick={() => { if (!blocked) ontest(Number(testMenuOpen), tt.key); }}
+				disabled={busy || blocked}
+				title={blocked ? t(tt.disabledReason!) : ''}
 				class="flex items-center gap-2 w-full px-3 py-1.5 text-sm rounded hover:bg-[var(--color-muted)] transition-colors disabled:opacity-50 text-left">
 				<MdiIcon name={tt.icon} size={14} />
 				{t(tt.labelKey)}
-				{#if ttTesting[`${testMenuOpen}_${tt.key}`]}
+				{#if blocked}
+					<MdiIcon name="mdiLock" size={12} />
+				{/if}
+				{#if busy}
 					<span class="ml-auto text-xs text-[var(--color-muted-foreground)]">...</span>
 				{/if}
 			</button>
+			{#if blocked}
+				<p class="px-3 pb-1 text-[10px]" style="color: var(--color-muted-foreground);">{t(tt.disabledReason!)}</p>
+			{/if}
 		{/each}
 	</div>
 {/if}

frontend/src/routes/notification-trackers/TrackerForm.svelte

@@ -4,6 +4,7 @@
 	import Card from '$lib/components/Card.svelte';
 	import IconPicker from '$lib/components/IconPicker.svelte';
 	import Hint from '$lib/components/Hint.svelte';
+	import MdiIcon from '$lib/components/MdiIcon.svelte';
 	import EntitySelect from '$lib/components/EntitySelect.svelte';
 	import MultiEntitySelect from '$lib/components/MultiEntitySelect.svelte';
 	import { getDescriptor } from '$lib/providers';
@@ -199,6 +200,22 @@
 		</div>
 		{/if}
 
+		<!-- Feature discovery: the periodic/scheduled/memory/quiet-hours controls
+		     live on the tracking config, not on the tracker itself. Surface this
+		     here so users don't have to stumble onto the feature by reading docs. -->
+		{#if providerType === 'immich'}
+		<div class="flex items-start gap-2 rounded-md border border-[var(--color-border)] bg-[var(--color-muted)]/30 px-3 py-2">
+			<span style="color: var(--color-primary);"><MdiIcon name="mdiInformationOutline" size={16} /></span>
+			<div class="flex-1 text-xs">
+				<p style="color: var(--color-muted-foreground);">{t('notificationTracker.featureDiscovery')}</p>
+				<a href="/tracking-configs" class="inline-flex items-center gap-1 text-[var(--color-primary)] hover:underline mt-1">
+					<MdiIcon name="mdiArrowRight" size={12} />
+					{t('notificationTracker.openTrackingConfig')}
+				</a>
+			</div>
+		</div>
+		{/if}
+
 		<button type="submit" disabled={submitting || linkCheckLoading} class="px-4 py-2 bg-[var(--color-primary)] text-[var(--color-primary-foreground)] rounded-md text-sm font-medium hover:opacity-90 disabled:opacity-50">
 			{#if linkCheckLoading}{t('notificationTracker.checkingLinks')}{:else}{editing ? t('common.save') : t('notificationTracker.createTracker')}{/if}
 		</button>

frontend/src/routes/template-configs/+page.svelte

@@ -42,6 +42,17 @@
 	let editing = $state<number | null>(null);
 	let error = $state('');
 	let confirmDelete = $state<{ id: number; onconfirm: () => Promise<void> } | null>(null);
+	/**
+	 * Reset-to-default confirmation prompt. ``kind: 'slot'`` confirms a
+	 * single-slot reset (slotKey populated); ``'all'`` confirms a full
+	 * locale-scoped wipe. Split from confirmDelete so the two flows can
+	 * coexist without stomping each other's state mid-dialog.
+	 */
+	let confirmReset = $state<{
+		kind: 'slot' | 'all';
+		slotKey?: string;
+		message: string;
+	} | null>(null);
 	let slotPreview = $state<Record<string, string>>({});
 	let slotErrors = $state<Record<string, string>>({});
 	let slotErrorLines = $state<Record<string, number | null>>({});
@@ -206,7 +217,40 @@
 				supportedLocalesCache.fetch(),
 			]);
 		} catch (err: any) { error = err.message || t('common.loadError'); snackError(error); }
-		finally { loaded = true; highlightFromUrl(); }
+		finally { loaded = true; highlightFromUrl(); handleDeepLink(); }
+	}
+
+	/**
+	 * Respond to ``?edit_slot=<slot_name>&provider=<type>`` deep-links from
+	 * other pages (currently the tracking-configs Preview-template modal).
+	 * Picks the first visible config matching ``provider``, opens it in edit
+	 * mode, and pre-expands the target slot. Strips the param from the URL so
+	 * a subsequent reload doesn't reopen the form unexpectedly.
+	 */
+	function handleDeepLink() {
+		if (typeof window === 'undefined') return;
+		const params = new URLSearchParams(window.location.search);
+		const slot = params.get('edit_slot');
+		if (!slot) return;
+		const provider = params.get('provider') || '';
+		const target = allTemplateConfigs.find(
+			c => !provider || c.provider_type === provider,
+		);
+		// Strip the deep-link param so reload/back doesn't replay it.
+		params.delete('edit_slot');
+		const qs = params.toString();
+		window.history.replaceState(null, '', window.location.pathname + (qs ? '?' + qs : ''));
+		if (!target) {
+			snackError(t('templateConfig.deepLinkNoConfig'));
+			return;
+		}
+		edit(target);
+		expandedSlots = new Set([slot]);
+		// Scroll the slot into view once the form has rendered.
+		setTimeout(() => {
+			const el = document.getElementById(`slot-${slot}`);
+			if (el) el.scrollIntoView({ behavior: 'smooth', block: 'start' });
+		}, 200);
 	}
 
 	function openNew() {
@@ -241,6 +285,65 @@
 		} catch (err: any) { error = err.message; snackError(err.message); }
 	}
 
+	/**
+	 * Ask the user to confirm a reset. The actual fetch+replace runs in
+	 * ``performReset`` after the ConfirmModal's onconfirm fires. Split into
+	 * two steps so we can use the app-wide ConfirmModal (consistent look,
+	 * keyboard handling) instead of ``window.confirm`` (blocks the page).
+	 */
+	function resetSlotToDefault(slotKey: string) {
+		if (!form.provider_type) return;
+		confirmReset = {
+			kind: 'slot',
+			slotKey,
+			message: t('templateConfig.resetSlotConfirm').replace('{locale}', activeLocale.toUpperCase()),
+		};
+	}
+
+	function resetAllToDefaults() {
+		if (!form.provider_type) return;
+		confirmReset = {
+			kind: 'all',
+			message: t('templateConfig.resetAllConfirm').replace(/\{locale\}/g, activeLocale.toUpperCase()),
+		};
+	}
+
+	async function performReset() {
+		if (!confirmReset || !form.provider_type) return;
+		const { kind, slotKey } = confirmReset;
+		confirmReset = null;
+		try {
+			if (kind === 'slot' && slotKey) {
+				const res = await api<Record<string, Record<string, string>>>(
+					`/template-configs/defaults?provider_type=${encodeURIComponent(form.provider_type)}&slot_name=${encodeURIComponent(slotKey)}&locale=${encodeURIComponent(activeLocale)}`,
+				);
+				const text = res?.[slotKey]?.[activeLocale];
+				if (!text) {
+					snackError(t('templateConfig.resetNoDefault'));
+					return;
+				}
+				setSlotValue(slotKey, text);
+				validateSlot(slotKey, text, true);
+			} else {
+				const res = await api<Record<string, Record<string, string>>>(
+					`/template-configs/defaults?provider_type=${encodeURIComponent(form.provider_type)}&locale=${encodeURIComponent(activeLocale)}`,
+				);
+				// Replace current-locale slots; leave other locales' values untouched.
+				const nextSlots = { ...form.slots };
+				for (const [key, localeMap] of Object.entries(res || {})) {
+					const text = localeMap?.[activeLocale];
+					if (text === undefined) continue;
+					nextSlots[key] = { ...(nextSlots[key] || {}), [activeLocale]: text };
+				}
+				form.slots = nextSlots;
+				refreshAllPreviews();
+			}
+			snackSuccess(t('templateConfig.resetApplied'));
+		} catch (err: any) {
+			snackError(err.message);
+		}
+	}
+
 	function clone(c: TemplateConfig) {
 		form = {
 			provider_type: c.provider_type,
@@ -321,7 +424,7 @@
 		</div>
 
 		<!-- Locale tabs -->
-		<div class="flex gap-1 mb-3 border-b border-[var(--color-border)]">
+		<div class="flex items-center gap-1 mb-3 border-b border-[var(--color-border)]">
 			{#each LOCALES as loc}
 				<button type="button"
 					class="px-3 py-1.5 text-xs font-medium rounded-t-md transition-colors {activeLocale === loc ? 'bg-[var(--color-primary)] text-[var(--color-primary-foreground)]' : 'text-[var(--color-muted-foreground)] hover:bg-[var(--color-muted)]'}"
@@ -329,6 +432,14 @@
 					{loc.toUpperCase()}
 				</button>
 			{/each}
+			{#if form.provider_type}
+				<button type="button" onclick={resetAllToDefaults}
+					title={t('templateConfig.resetAllToDefaults')}
+					class="ml-auto flex items-center gap-1 text-xs px-2 py-1 rounded-md border border-[var(--color-border)] text-[var(--color-muted-foreground)] hover:bg-[var(--color-muted)]">
+					<MdiIcon name="mdiRefresh" size={12} />
+					{t('templateConfig.resetAllToDefaults')}
+				</button>
+			{/if}
 		</div>
 
 		<!-- Slot filter -->
@@ -361,6 +472,7 @@
 								{/if}
 							</div>
 						{:else}
+							<div id="slot-{slot.key}">
 							<CollapsibleSlot
 								label={slot.key}
 								description={slot.description || t(`templateConfig.${slot.label}`, slot.label)}
@@ -379,6 +491,11 @@
 										<button type="button" onclick={() => showVarsFor = slot.key}
 											class="text-xs text-[var(--color-muted-foreground)] hover:underline">{t('templateConfig.variables')}</button>
 									{/if}
+									<button type="button" onclick={() => resetSlotToDefault(slot.key)}
+										title={t('templateConfig.resetToDefault')}
+										class="text-xs text-[var(--color-muted-foreground)] hover:underline">
+										{t('templateConfig.resetToDefault')}
+									</button>
 								</div>
 
 								{#if showPreviewFor.has(slot.key) && slotPreview[slot.key] && !slotErrors[slot.key]}
@@ -397,6 +514,7 @@
 									{/if}
 								{/if}
 							</CollapsibleSlot>
+							</div>
 						{/if}
 					{/each}
 				</div>
@@ -466,6 +584,14 @@
 <ConfirmModal open={confirmDelete !== null} message={t('templateConfig.confirmDelete')}
 	onconfirm={() => confirmDelete?.onconfirm()} oncancel={() => confirmDelete = null} />
 
+<ConfirmModal open={confirmReset !== null}
+	title={t('templateConfig.resetToDefault')}
+	message={confirmReset?.message || ''}
+	confirmLabel={confirmReset?.kind === 'all' ? t('templateConfig.resetAllToDefaults') : t('templateConfig.resetToDefault')}
+	confirmIcon="mdiRefresh"
+	onconfirm={performReset}
+	oncancel={() => confirmReset = null} />
+
 <BlockedByModal open={!!blockedBy} detail={blockedBy} onclose={() => blockedBy = null} />
 
 <!-- Variables reference modal -->

frontend/src/routes/tracking-configs/+page.svelte

@@ -12,6 +12,9 @@
 	import MdiIcon from '$lib/components/MdiIcon.svelte';
 	import EmptyState from '$lib/components/EmptyState.svelte';
 	import ConfirmModal from '$lib/components/ConfirmModal.svelte';
+	import Modal from '$lib/components/Modal.svelte';
+	import { sanitizePreview } from '$lib/sanitize';
+	import { supportedLocalesCache } from '$lib/stores/caches.svelte';
 	import Hint from '$lib/components/Hint.svelte';
 	import IconButton from '$lib/components/IconButton.svelte';
 	import IconGridSelect from '$lib/components/IconGridSelect.svelte';
@@ -22,13 +25,150 @@
 	import { getDescriptor, buildTrackingFormDefaults } from '$lib/providers';
 	import ErrorBanner from '$lib/components/ErrorBanner.svelte';
 	import Button from '$lib/components/Button.svelte';
-	import type { TrackingConfig } from '$lib/types';
 
 	/** Grid-select item source lookup — maps descriptor string name to actual function. */
 	const gridItemSources: Record<string, () => any[]> = {
 		sortByItems, sortOrderItems, albumModeItems, assetTypeItems, memorySourceItems,
 	};
 
+	/**
+	 * HH:MM, comma-separated: "09:00" or "09:00, 18:30" — the only format cron
+	 * dispatch accepts. Matched on blur for time-list fields; invalid values
+	 * are surfaced inline next to the input.
+	 */
+	const TIME_LIST_RE = /^\s*(?:[01]\d|2[0-3]):[0-5]\d(?:\s*,\s*(?:[01]\d|2[0-3]):[0-5]\d)*\s*$/;
+
+	/** Per-field error messages surfaced inline under time-list inputs. */
+	let timeListErrors = $state<Record<string, string>>({});
+
+	/** Normalize "9:0 , 18:30" → "09:00,18:30" on blur, clear error when valid. */
+	function normalizeTimeList(key: string) {
+		const raw = String(form[key] ?? '').trim();
+		if (!raw) { timeListErrors = { ...timeListErrors, [key]: '' }; return; }
+		if (!TIME_LIST_RE.test(raw)) {
+			// Try a lenient normalization: split on commas, zero-pad each part.
+			const parts = raw.split(',').map(p => p.trim()).filter(Boolean);
+			const fixed: string[] = [];
+			let ok = true;
+			for (const p of parts) {
+				const m = /^(\d{1,2}):(\d{1,2})$/.exec(p);
+				if (!m) { ok = false; break; }
+				const hh = Number(m[1]);
+				const mm = Number(m[2]);
+				if (!Number.isFinite(hh) || !Number.isFinite(mm) || hh < 0 || hh > 23 || mm < 0 || mm > 59) { ok = false; break; }
+				fixed.push(`${String(hh).padStart(2, '0')}:${String(mm).padStart(2, '0')}`);
+			}
+			if (ok) {
+				form[key] = fixed.join(',');
+				timeListErrors = { ...timeListErrors, [key]: '' };
+				return;
+			}
+			timeListErrors = { ...timeListErrors, [key]: t('trackingConfig.invalidTimeList') };
+			return;
+		}
+		// Canonicalise spacing.
+		form[key] = raw.split(',').map(s => s.trim()).join(',');
+		timeListErrors = { ...timeListErrors, [key]: '' };
+	}
+
+	/**
+	 * Quiet-hours preview: "22:00 → 07:00 next day (9h)" or "Quiet period is 0
+	 * minutes — adjust times" when start equals end. Handles overnight ranges
+	 * (start > end) correctly.
+	 */
+	function quietHoursPreview(start: string, end: string): string {
+		if (!start || !end) return '';
+		const [sh, sm] = start.split(':').map(Number);
+		const [eh, em] = end.split(':').map(Number);
+		if (![sh, sm, eh, em].every(Number.isFinite)) return '';
+		const sMin = sh * 60 + sm;
+		const eMin = eh * 60 + em;
+		if (sMin === eMin) return t('trackingConfig.quietHoursZero');
+		const overnight = sMin > eMin;
+		const span = overnight ? (24 * 60 - sMin) + eMin : eMin - sMin;
+		const h = Math.floor(span / 60);
+		const m = span % 60;
+		const dur = m === 0 ? `${h}h` : `${h}h ${m}m`;
+		const arrow = overnight
+			? `${start} → ${end} ${t('trackingConfig.nextDay')}`
+			: `${start} → ${end}`;
+		return `${arrow} (${dur})`;
+	}
+
+	function gotoTemplateConfig(slotName: string) {
+		// Deep-link to the template configs page: pass the slot as a query
+		// param (``edit_slot``) so the destination can auto-open the first
+		// matching config in edit mode and expand that slot. Plain hashes
+		// like ``#slot-X`` were a no-op because slots don't exist in the DOM
+		// until a config is being edited.
+		const u = new URL('/template-configs', window.location.origin);
+		u.searchParams.set('provider', 'immich');
+		u.searchParams.set('edit_slot', slotName);
+		window.location.href = u.toString();
+	}
+
+	/**
+	 * Inline preview of the shipped default template for a scheduled/periodic/
+	 * memory slot. Using the shipped default (not a tracker's current template)
+	 * keeps this scoped to the tracking-config page — which has no concept of
+	 * which TemplateConfig a given tracker uses. Users who want to edit the
+	 * actual config can click "Edit template" in the modal footer.
+	 *
+	 * ``previewLocale`` is modal-scoped so switching tabs only refetches for
+	 * this preview — the user's UI locale (and other previews) are untouched.
+	 */
+	let previewModal = $state<{ slotName: string; rendered: string; error: string; locale: string } | null>(null);
+	let previewLoading = $state(false);
+	let previewLocales = $derived(supportedLocalesCache.items);
+
+	async function openTemplatePreview(slotName: string) {
+		await supportedLocalesCache.fetch();
+		const initialLocale = previewLocales.includes('en') ? 'en' : (previewLocales[0] || 'en');
+		await renderPreviewFor(slotName, initialLocale);
+	}
+
+	async function renderPreviewFor(slotName: string, locale: string) {
+		previewLoading = true;
+		try {
+			const defaults = await api<Record<string, Record<string, string>>>(
+				`/template-configs/defaults?provider_type=immich&slot_name=${encodeURIComponent(slotName)}&locale=${encodeURIComponent(locale)}`,
+			);
+			const template = defaults?.[slotName]?.[locale];
+			if (!template) {
+				previewModal = { slotName, rendered: '', error: t('templateConfig.resetNoDefault'), locale };
+				return;
+			}
+			const res = await api<{ rendered?: string; error?: string }>(
+				'/template-configs/preview-raw',
+				{
+					method: 'POST',
+					body: JSON.stringify({
+						template,
+						target_type: 'telegram',
+						date_format: '%d.%m.%Y, %H:%M UTC',
+						date_only_format: '%d.%m.%Y',
+					}),
+				},
+			);
+			previewModal = {
+				slotName,
+				rendered: res?.rendered || '',
+				error: res?.error || '',
+				locale,
+			};
+		} catch (err: any) {
+			previewModal = { slotName, rendered: '', error: err.message, locale };
+		} finally {
+			previewLoading = false;
+		}
+	}
+
+	const SLOT_FOR_SECTION: Record<string, string> = {
+		periodic: 'periodic_summary_message',
+		scheduled: 'scheduled_assets_message',
+		memory: 'memory_mode_message',
+	};
+
 	let allConfigs = $derived(trackingConfigsCache.items);
 	let filterText = $state('');
 	let filterType = $state('');
@@ -161,10 +301,20 @@
 				{t(section.legend)}
 				{#if section.legendHint}<Hint text={t(section.legendHint)} />{/if}
 			</legend>
-			<label class="flex items-center gap-2 text-sm mt-1">
-				<input type="checkbox" bind:checked={form[section.enabledField]} />
-				{t('trackingConfig.enabled')}
-			</label>
+			<div class="flex items-center justify-between mt-1">
+				<label class="flex items-center gap-2 text-sm">
+					<input type="checkbox" bind:checked={form[section.enabledField]} />
+					{t('trackingConfig.enabled')}
+				</label>
+				{#if SLOT_FOR_SECTION[section.key]}
+					<button type="button" onclick={() => openTemplatePreview(SLOT_FOR_SECTION[section.key])}
+						class="text-xs text-[var(--color-primary)] hover:underline inline-flex items-center gap-1"
+						disabled={previewLoading}>
+						<MdiIcon name="mdiEyeOutline" size={14} />
+						{t('trackingConfig.previewTemplate')}
+					</button>
+				{/if}
+			</div>
 			{#if form[section.enabledField]}
 			<div class="grid grid-cols-3 gap-3 mt-3">
 				{#each section.fields as field (field.key)}
@@ -181,17 +331,32 @@
 						{:else if field.type === 'grid-select' && field.gridItems}
 							<IconGridSelect items={gridItemSources[field.gridItems]()} bind:value={form[field.key]} columns={field.gridColumns ?? 2} compact />
 						{:else}
-							<input type={field.key.includes('date') ? 'date'
-									: field.key.startsWith('quiet_hours_') ? 'time'
-									: field.key.includes('times') ? 'text'
-									: 'number'}
+							{@const inputType = field.type === 'date' ? 'date'
+								: field.type === 'time' ? 'time'
+								: field.type === 'time-list' ? 'text'
+								: 'number'}
+							{@const hasError = field.type === 'time-list' && !!timeListErrors[field.key]}
+							<input type={inputType}
 								bind:value={form[field.key]} min={field.min} max={field.max}
-								placeholder={field.key.includes('times') || field.key.startsWith('quiet_hours_') ? String(field.defaultValue ?? '') : ''}
-								class="w-full px-2 py-1 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]" />
+								onblur={field.type === 'time-list' && field.validateFormat ? () => normalizeTimeList(field.key) : undefined}
+								placeholder={field.type === 'time-list' || field.type === 'time' ? String(typeof field.defaultValue === 'function' ? field.defaultValue() : (field.defaultValue ?? '')) : ''}
+								class="w-full px-2 py-1 border rounded-md text-sm bg-[var(--color-background)] {hasError ? 'border-[var(--color-error-fg)]' : 'border-[var(--color-border)]'}" />
+							{#if field.inlineHelp}
+								<p class="text-[10px] mt-0.5" style="color: var(--color-muted-foreground);">{t(field.inlineHelp)}</p>
+							{/if}
+							{#if hasError}
+								<p class="text-[10px] mt-0.5" style="color: var(--color-error-fg);">{timeListErrors[field.key]}</p>
+							{/if}
 						{/if}
 					</div>
 				{/each}
 			</div>
+			{#if section.key === 'quietHours' && form.quiet_hours_start && form.quiet_hours_end}
+				<p class="text-xs mt-2" style="color: var(--color-muted-foreground);">
+					<MdiIcon name="mdiWeatherNight" size={12} />
+					{quietHoursPreview(String(form.quiet_hours_start), String(form.quiet_hours_end))}
+				</p>
+			{/if}
 			{/if}
 		</fieldset>
 		{/each}
@@ -268,7 +433,63 @@
 
 <BlockedByModal open={!!blockedBy} detail={blockedBy} onclose={() => blockedBy = null} />
 
+<Modal open={previewModal !== null}
+	title={previewModal ? `${t('trackingConfig.previewTemplate')} — ${previewModal.slotName}` : ''}
+	onclose={() => previewModal = null}>
+	{#if previewModal}
+		{#if previewLocales.length > 1}
+			<div class="flex gap-1 mb-3 border-b border-[var(--color-border)]">
+				{#each previewLocales as loc}
+					<button type="button"
+						onclick={() => renderPreviewFor(previewModal!.slotName, loc)}
+						disabled={previewLoading}
+						class="px-3 py-1.5 text-xs font-medium rounded-t-md transition-colors {previewModal.locale === loc ? 'bg-[var(--color-primary)] text-[var(--color-primary-foreground)]' : 'text-[var(--color-muted-foreground)] hover:bg-[var(--color-muted)]'} disabled:opacity-50">
+						{loc.toUpperCase()}
+					</button>
+				{/each}
+			</div>
+		{/if}
+		<p class="text-xs mb-3" style="color: var(--color-muted-foreground);">
+			{t('trackingConfig.previewSampleNote')}
+		</p>
+		<!-- Keep the prior rendered/error box mounted while refetching on locale
+		     switch — just dim it. Unmounting and replacing with a small "…"
+		     placeholder caused a one-frame layout jump as the modal shrank and
+		     then re-expanded. -->
+		<div class="relative mb-3" style="opacity: {previewLoading ? 0.5 : 1}; transition: opacity 0.15s ease;">
+			{#if previewModal.error}
+				<div class="p-3 rounded text-xs" style="background: var(--color-error-bg); color: var(--color-error-fg);">
+					{previewModal.error}
+				</div>
+			{:else if previewModal.rendered}
+				<div class="p-3 bg-[var(--color-muted)] rounded text-sm preview-html">
+					<pre class="whitespace-pre-wrap text-xs">{@html sanitizePreview(previewModal.rendered)}</pre>
+				</div>
+			{:else}
+				<div class="p-3 text-xs" style="color: var(--color-muted-foreground);">…</div>
+			{/if}
+		</div>
+		<div class="flex gap-2 justify-end mt-3">
+			<button type="button" onclick={() => { const s = previewModal!.slotName; previewModal = null; gotoTemplateConfig(s); }}
+				class="text-xs px-3 py-1.5 rounded-md border border-[var(--color-border)] hover:bg-[var(--color-muted)]">
+				{t('trackingConfig.editTemplate')}
+			</button>
+			<button type="button" onclick={() => previewModal = null}
+				class="text-xs px-3 py-1.5 rounded-md bg-[var(--color-primary)] text-[var(--color-primary-foreground)]">
+				{t('common.close')}
+			</button>
+		</div>
+	{/if}
+</Modal>
+
 <style>
+	:global(.preview-html a) {
+		color: var(--color-primary);
+		text-decoration: underline;
+	}
+	:global(.preview-html a:hover) {
+		opacity: 0.8;
+	}
 	.toggle-switch {
 		position: relative;
 		display: inline-flex;