Add tooltip hints to form fields, fix navigation overlap bug

- Create Hint component with fixed-position floating tooltip
- Add hints to tracking configs (periodic/scheduled/memory modes,
  favorites, times, album mode, rating), template configs (section
  legends), targets (AI captions, media settings, config selectors),
  and trackers (scan interval)
- Add 21 hint i18n keys in EN and RU
- Fix transition:slide → in:slide on all pages to prevent content
  overlap when navigating away mid-animation
- Merge Asset Display into Event Tracking fieldset; use consistent
  "Max Assets" label with hint in each section

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/routes/servers/+page.svelte

@@ -91,7 +91,7 @@
 {/if}
 
 {#if showForm}
-	<div transition:slide={{ duration: 200 }}>
+	<div in:slide={{ duration: 200 }}>
 	<Card class="mb-6">
 		{#if error}<div class="bg-[var(--color-error-bg)] text-[var(--color-error-fg)] text-sm rounded-md p-3 mb-4">{error}</div>{/if}
 		<form onsubmit={save} class="space-y-3">