feat(trackers): user filters for Gitea, webhook polling cleanup, dashboard navigability

- Gitea: NotificationTracker now exposes sender allowlist / blocklist filters
  via MultiEntitySelect, populated from Gitea /users/search merged with past
  EventLog senders so the picker is useful before the first webhook arrives.
- Webhook providers (gitea, planka, webhook): stop scheduling interval polling
  jobs on tracker create/update/startup; hide the "every Xs" indicator in the
  tracker list since there is no polling.
- Dashboard: stat cards are now <a> links that route to providers, trackers,
  targets, command-trackers, or scroll to the events panel. Provider deck
  rows highlight the target provider on click.
- Command trackers / command configs: auto-reselect the right config when the
  provider type changes (matches notification-tracker behavior).
- Migration: drop legacy batch_duration column from notification_tracker —
  the field is gone from the model but its NOT NULL constraint blocked
  inserts on older DBs.
- Docs: refresh entity-relationships.md with current NotificationTracker
  fields (filters, adaptive_max_skip, default_*_config_id).

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

@@ -23,6 +23,7 @@
 		};
 		providerItems: { value: number; label: string; icon: string; desc: string }[];
 		collections: any[];
+		users?: { id: string; name: string }[];
 		collectionFilter?: string;
 		trackingConfigItems?: { value: number; label: string; icon: string }[];
 		templateConfigItems?: { value: number; label: string; icon: string }[];
@@ -40,6 +41,7 @@
 		form = $bindable(),
 		providerItems,
 		collections,
+		users = [],
 		collectionFilter = $bindable(),
 		trackingConfigItems = [],
 		templateConfigItems = [],
@@ -116,6 +118,21 @@
 			</div>
 		{/if}
 
+		{#if descriptor?.userFilters && descriptor.userFilters.length > 0}
+			{@const userItems = users.map(u => ({ value: u.id, label: u.name }))}
+			{#each descriptor.userFilters as uf (uf.key)}
+				<div>
+					<div class="block text-sm font-medium mb-1">{t(uf.label)}</div>
+					<MultiEntitySelect
+						items={userItems.map(i => ({ ...i, icon: uf.icon }))}
+						values={form.filters[uf.key] || []}
+						onchange={(vals) => form.filters = { ...form.filters, [uf.key]: vals }}
+						placeholder={t(uf.placeholder)}
+					/>
+				</div>
+			{/each}
+		{/if}
+
 		{#if isScheduler}
 			<!-- Schedule type -->
 			<fieldset class="border border-[var(--color-border)] rounded-md p-3">