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/lib/i18n/en.json

@@ -267,6 +267,29 @@
 		"preview": "Preview",
 		"confirmDelete": "Delete this template config?"
 	},
+	"hints": {
+		"periodicSummary": "Sends a scheduled summary of all tracked albums at specified times. Great for daily/weekly digests.",
+		"scheduledAssets": "Sends random or selected photos from tracked albums on a schedule. Like a daily photo pick.",
+		"memoryMode": "\"On This Day\" — sends photos taken on this date in previous years. Nostalgic flashbacks.",
+		"favoritesOnly": "Only include assets marked as favorites in Immich.",
+		"maxAssets": "Maximum number of asset details to include in a single notification message.",
+		"periodicStartDate": "The reference date for calculating periodic intervals. Summaries are sent every N days from this date.",
+		"times": "Time(s) of day to send notifications, in HH:MM format. Use commas for multiple times: 09:00,18:00",
+		"albumMode": "Per album: separate notification per album. Combined: one notification with all albums. Random: pick one album randomly.",
+		"minRating": "Only include assets with at least this star rating (0 = no filter).",
+		"eventMessages": "Templates for real-time event notifications. Use {variables} for dynamic content.",
+		"assetFormatting": "How individual assets are formatted within notification messages.",
+		"dateLocation": "Date and location formatting in notifications. Uses strftime syntax for dates.",
+		"scheduledMessages": "Templates for periodic summaries, scheduled photo picks, and On This Day memories.",
+		"aiCaptions": "Use Claude AI to generate a natural-language caption for notifications instead of the template.",
+		"maxMedia": "Maximum number of photos/videos to attach per notification (0 = text only).",
+		"groupSize": "Telegram media groups can contain 2-10 items. Larger batches are split into chunks.",
+		"chunkDelay": "Delay in milliseconds between sending media chunks. Prevents Telegram rate limiting.",
+		"maxAssetSize": "Skip assets larger than this size in MB. Telegram limits files to 50 MB.",
+		"trackingConfig": "Controls which events trigger notifications and how assets are filtered.",
+		"templateConfig": "Controls the message format. Uses default templates if not set.",
+		"scanInterval": "How often to poll the Immich server for changes, in seconds. Lower = faster detection but more API calls."
+	},
 	"common": {
 		"loading": "Loading...",
 		"save": "Save",