feat(i18n): add filter/sort labels and playlist types

Update English, German, and Russian locale files to improve playlist
UI text and provide explicit playlist type labels.

- Rename and adjust several labels: change FILTER_BY_TYPE to a more
  descriptive "Playlist Types" and add a new FILTER_AND_SORT string.
- Normalize capitalization for SORT_BY ("Sort By") in en.json.
- Add PLAYLIST_TYPES object with keys for M3U, XTREAM, and STALKER,
  providing localized descriptions for each language.
- Keep existing sorting options and parsing messages intact.

These changes make filtering, sorting, and playlist source options
clearer to users in multiple locales and prepare the UI for showing
playlist type choices.

apps/web/src/assets/i18n/de.json

@@ -150,8 +150,9 @@
             "MAC_ADDRESS": "Mac-Adresse",
             "URL_VALIDATION_ERROR": "Sollte eine gültige URL mit Protokoll sein (z. B. http://example.com/c oder https://example.com/stalker_portal/c)"
         },
-        "FILTER_BY_TYPE": "Nach Typ filtern",
+        "FILTER_BY_TYPE": "Playlist-Typen",
         "FILTER_BY_NAME": "Nach Namen filtern",
+        "FILTER_AND_SORT": "Filtern & Sortieren",
         "SORT_PLAYLISTS": "Playlisten sortieren",
         "SORT_BY": "Sortieren nach",
         "SORT_OPTIONS": {
@@ -160,6 +161,11 @@
             "NEWEST": "Hinzugefügt (Neueste zuerst)",
             "OLDEST": "Hinzugefügt (Älteste zuerst)"
         },
+        "PLAYLIST_TYPES": {
+            "M3U": "M3U (lokal, URL, Text)",
+            "XTREAM": "Xtream",
+            "STALKER": "Stalker"
+        },
         "IMPORTED_AS_TEXT": "Als Text importiert",
         "PARSING_ERROR": "Fehler: Parsen fehlgeschlagen, keine gültige Playlist:"
     },

apps/web/src/assets/i18n/en.json

@@ -112,15 +112,21 @@
             "ADD": "Add"
         },
         "FILTER_BY_NAME": "Filter by name",
-        "FILTER_BY_TYPE": "Filter by type",
+        "FILTER_BY_TYPE": "Playlist Types",
+        "FILTER_AND_SORT": "Filter & Sort",
         "SORT_PLAYLISTS": "Sort playlists",
-        "SORT_BY": "Sort by",
+        "SORT_BY": "Sort By",
         "SORT_OPTIONS": {
             "NAME_ASC": "Name (A-Z)",
             "NAME_DESC": "Name (Z-A)",
             "NEWEST": "Date added (Newest first)",
             "OLDEST": "Date added (Oldest first)"
         },
+        "PLAYLIST_TYPES": {
+            "M3U": "M3U (local, url, text)",
+            "XTREAM": "Xtream",
+            "STALKER": "Stalker"
+        },
         "IMPORTED_AS_TEXT": "Imported as text",
         "PARSING_ERROR": "Error: Parsing failed, not a valid playlist:"
     },

apps/web/src/assets/i18n/ru.json

@@ -109,8 +109,9 @@
             "SERVER_URL": "URL сервера",
             "URL_VALIDATION_ERROR": "Должен быть действительный URL-адрес с протоколом (например, http://example.com/c или https://example.com/stalker_portal/c)."
         },
-        "FILTER_BY_TYPE": "Фильтровать по типу",
+        "FILTER_BY_TYPE": "Типы плейлистов",
         "FILTER_BY_NAME": "Фильтровать по имени",
+        "FILTER_AND_SORT": "Фильтр и сортировка",
         "SORT_PLAYLISTS": "Сортировать плейлисты",
         "SORT_BY": "Сортировать по",
         "SORT_OPTIONS": {
@@ -119,6 +120,11 @@
             "NEWEST": "Дате добавления (сначала новые)",
             "OLDEST": "Дате добавления (сначала старые)"
         },
+        "PLAYLIST_TYPES": {
+            "M3U": "M3U (локально, URL, текст)",
+            "XTREAM": "Xtream",
+            "STALKER": "Stalker"
+        },
         "IMPORTED_AS_TEXT": "Импортировано как текст",
         "PARSING_ERROR": "Ошибка парсинга, недействительный плейлист:"
     },