refactor: remove all playlist support, fix message ordering

- Remove playlist handler, keyboard, and all related callback routing
- Strip playlist parameter from YouTube Music radio URLs, reject pure playlists
- Send media preview before format selection prompt (correct ordering)
- Remove DetectPlaylist/GetPlaylistInfo methods (no longer needed)
- Remove IsPlaylist, PlaylistCount, PlaylistEntries from MediaInfo
- Remove PlaylistState struct, keep PlaylistEntry for search results
- Update README to reflect removal of playlist feature

internal/handler/keyboard.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 
 	"github.com/go-telegram/bot/models"
-
-	"uptodownBot/internal/domain"
 )
 
 func mainKeyboard() models.InlineKeyboardMarkup {
@@ -82,87 +80,6 @@ func progressKeyboard(pct float64, speed, eta string) models.InlineKeyboardMarku
 	}
 }
 
-// playlistNavKeyboard builds the paginated navigation for playlist selection.
-func playlistNavKeyboard(state *domain.PlaylistState, selectedCount int) models.InlineKeyboardMarkup {
-	totalPages := (len(state.Entries) + state.PerPage - 1) / state.PerPage
-	if totalPages < 1 {
-		totalPages = 1
-	}
-
-	// Build entry rows (2 per row)
-	rows := [][]models.InlineKeyboardButton{}
-	start := state.Page * state.PerPage
-	end := start + state.PerPage
-	if end > len(state.Entries) {
-		end = len(state.Entries)
-	}
-
-	for i := start; i < end; i += 2 {
-		row := []models.InlineKeyboardButton{}
-		// First entry
-		e := state.Entries[i]
-		prefix := "  "
-		if state.Selected[e.ID] {
-			prefix = "> "
-		}
-		// Truncate title for button
-		title := e.Title
-		if len(title) > 30 {
-			title = title[:27] + "..."
-		}
-		row = append(row, models.InlineKeyboardButton{
-			Text: prefix + title, CallbackData: "pl_entry_" + e.ID,
-		})
-		// Second entry if available
-		if i+1 < end {
-			e2 := state.Entries[i+1]
-			prefix2 := "  "
-			if state.Selected[e2.ID] {
-				prefix2 = "> "
-			}
-			title2 := e2.Title
-			if len(title2) > 30 {
-				title2 = title2[:27] + "..."
-			}
-			row = append(row, models.InlineKeyboardButton{
-				Text: prefix2 + title2, CallbackData: "pl_entry_" + e2.ID,
-			})
-		}
-		rows = append(rows, row)
-	}
-
-	// Navigation row
-	navRow := []models.InlineKeyboardButton{}
-	navRow = append(navRow, models.InlineKeyboardButton{
-		Text: "<", CallbackData: fmt.Sprintf("pl_page_%d", state.Page-1),
-	})
-	navRow = append(navRow, models.InlineKeyboardButton{
-		Text: fmt.Sprintf("Page %d/%d", state.Page+1, totalPages), CallbackData: "noop",
-	})
-	navRow = append(navRow, models.InlineKeyboardButton{
-		Text: ">", CallbackData: fmt.Sprintf("pl_page_%d", state.Page+1),
-	})
-	rows = append(rows, navRow)
-
-	// Action row
-	actionRow := []models.InlineKeyboardButton{
-		{Text: "Select All", CallbackData: "pl_select_all"},
-	}
-	if selectedCount > 0 {
-		actionRow = append(actionRow, models.InlineKeyboardButton{
-			Text: fmt.Sprintf("Confirm (%d)", selectedCount), CallbackData: "pl_confirm",
-		})
-	}
-	rows = append(rows, actionRow)
-
-	// Cancel
-	rows = append(rows, []models.InlineKeyboardButton{
-		{Text: "Cancel", CallbackData: "cancel_dl"},
-	})
-
-	return models.InlineKeyboardMarkup{InlineKeyboard: rows}
-}
-
 // deleteConfirmKeyboard builds the confirmation prompt for account deletion.
 func deleteConfirmKeyboard(userID int64) models.InlineKeyboardMarkup {
 	return models.InlineKeyboardMarkup{