Add frontend for TrackingConfig + TemplateConfig, fix locale, simplify trackers

New pages:
- /tracking-configs: Full CRUD with event tracking, asset display,
  periodic summary, scheduled assets, and memory mode sections.
  Collapsible sub-sections that show/hide based on enabled state.
- /template-configs: Full CRUD with all 21 template slots organized
  into 5 fieldsets (event messages, asset formatting, date/location,
  scheduled messages, telegram). Preview support per slot.

Updated pages:
- Targets: added tracking_config_id + template_config_id selectors
  (dropdowns populated from configs). Configs are reusable.
- Trackers: simplified to album selection + scan interval + targets.
  Added Test, Test Periodic, Test Memory buttons per tracker.
- Nav: replaced Templates with Tracking + Templates config links

Other fixes:
- Language button: now triggers window.location.reload() to force
  all child pages to re-evaluate t() calls
- Dark theme buttons: changed primary color to dark gray in dark mode
- Removed old /templates page (replaced by /template-configs)
- Added .gitignore for __pycache__ in server package

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

frontend/src/lib/i18n/en.json

@@ -7,7 +7,8 @@
 		"dashboard": "Dashboard",
 		"servers": "Servers",
 		"trackers": "Trackers",
-		"templates": "Templates",
+		"trackingConfigs": "Tracking",
+		"templateConfigs": "Templates",
 		"targets": "Targets",
 		"users": "Users",
 		"logout": "Logout"
@@ -157,6 +158,75 @@
 		"confirmDelete": "Delete this user?",
 		"joined": "joined"
 	},
+	"trackingConfig": {
+		"title": "Tracking Configs",
+		"description": "Define what events and assets to react to",
+		"newConfig": "New Config",
+		"name": "Name",
+		"namePlaceholder": "Default tracking",
+		"noConfigs": "No tracking configs yet.",
+		"eventTracking": "Event Tracking",
+		"assetsAdded": "Assets added",
+		"assetsRemoved": "Assets removed",
+		"albumRenamed": "Album renamed",
+		"albumDeleted": "Album deleted",
+		"trackImages": "Track images",
+		"trackVideos": "Track videos",
+		"favoritesOnly": "Favorites only",
+		"assetDisplay": "Asset Display",
+		"includePeople": "Include people",
+		"includeDetails": "Include asset details",
+		"maxAssets": "Max assets to show",
+		"sortBy": "Sort by",
+		"sortOrder": "Sort order",
+		"periodicSummary": "Periodic Summary",
+		"enabled": "Enabled",
+		"intervalDays": "Interval (days)",
+		"startDate": "Start date",
+		"times": "Times (HH:MM)",
+		"scheduledAssets": "Scheduled Assets",
+		"albumMode": "Album mode",
+		"limit": "Limit",
+		"assetType": "Asset type",
+		"minRating": "Min rating",
+		"memoryMode": "Memory Mode (On This Day)",
+		"test": "Test"
+	},
+	"templateConfig": {
+		"title": "Template Configs",
+		"description": "Define how notification messages are formatted",
+		"newConfig": "New Config",
+		"name": "Name",
+		"namePlaceholder": "Default EN",
+		"noConfigs": "No template configs yet.",
+		"eventMessages": "Event Messages",
+		"assetsAdded": "Assets added",
+		"assetsRemoved": "Assets removed",
+		"albumRenamed": "Album renamed",
+		"albumDeleted": "Album deleted",
+		"assetFormatting": "Asset Formatting",
+		"imageTemplate": "Image item",
+		"videoTemplate": "Video item",
+		"assetsWrapper": "Assets wrapper",
+		"moreMessage": "More message",
+		"peopleFormat": "People format",
+		"dateLocation": "Date & Location",
+		"dateFormat": "Date format",
+		"commonDate": "Common date",
+		"uniqueDate": "Per-asset date",
+		"locationFormat": "Location format",
+		"commonLocation": "Common location",
+		"uniqueLocation": "Per-asset location",
+		"favoriteIndicator": "Favorite indicator",
+		"scheduledMessages": "Scheduled Messages",
+		"periodicSummary": "Periodic summary",
+		"periodicAlbum": "Per-album item",
+		"scheduledAssets": "Scheduled assets",
+		"memoryMode": "Memory mode",
+		"telegramSettings": "Telegram",
+		"videoWarning": "Video warning",
+		"preview": "Preview"
+	},
 	"common": {
 		"loading": "Loading...",
 		"save": "Save",
@@ -171,6 +241,8 @@
 		"theme": "Theme",
 		"light": "Light",
 		"dark": "Dark",
-		"system": "System"
+		"system": "System",
+		"test": "Test",
+		"create": "Create"
 	}
 }