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/download.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"time"
 
@@ -20,18 +21,17 @@ import (
 )
 
 type stepState struct {
-	URL           string
-	MediaInfo     *domain.MediaInfo
-	Step          int
-	MainFormatID  string
-	MainFormat    *domain.Format
-	SecondaryID   string
-	SecondaryFmt  *domain.Format
-	Language      string
-	FormatIDs     []string
-	PlaylistState *domain.PlaylistState
-	SearchState   *domain.SearchState
-	CreatedAt     time.Time
+	URL          string
+	MediaInfo    *domain.MediaInfo
+	Step         int
+	MainFormatID string
+	MainFormat   *domain.Format
+	SecondaryID  string
+	SecondaryFmt *domain.Format
+	Language     string
+	FormatIDs    []string
+	SearchState  *domain.SearchState
+	CreatedAt    time.Time
 }
 
 const stepStateTTL = 30 * time.Minute
@@ -59,6 +59,25 @@ func (h *Handler) clearStepState(chatID int64) {
 	delete(h.stepStates, chatID)
 }
 
+// stripPlaylistParam removes the list parameter from YouTube/Music URLs.
+// Playlists are not supported; this converts a video-with-playlist URL (e.g. a
+// YouTube Music radio) to a plain video URL. Pure playlist URLs are rejected.
+func stripPlaylistParam(rawURL string) (string, bool) {
+	// Reject pure playlist URLs (https://youtube.com/playlist?list=...)
+	if strings.Contains(rawURL, "/playlist") || strings.Contains(rawURL, "youtube.com/pL") {
+		return "", false
+	}
+	// Strip the list query parameter from watch URLs
+	url := rawURL
+	if strings.Contains(url, "list=") {
+		// Remove &list=... or ?list=...
+		url = regexp.MustCompile(`[?&]list=[^&]+`).ReplaceAllString(url, "")
+		// Clean up trailing ? or & if the param was the only one
+		url = strings.TrimRight(url, "?&")
+	}
+	return url, true
+}
+
 // handleURLInput is the entry point when a user sends a URL or types in Download mode.
 func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string, userID int64) {
 	url, ok := domain.ValidateURL(text)
@@ -67,26 +86,15 @@ func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string,
 		return
 	}
 
-	if job := h.getActiveJob(userID); job != nil {
-		h.sendText(ctx, chatID, "You already have an active download. Cancel it first.")
+	// Strip playlist parameter and reject pure playlists.
+	url, ok = stripPlaylistParam(url)
+	if !ok {
+		h.sendText(ctx, chatID, "Playlists are not supported. Send a single video/audio URL.")
 		return
 	}
 
-	// Show a temporary status message that we will edit with results later.
-	fetchingMsg, _ := h.Bot.SendMessage(ctx, &tgbot.SendMessageParams{
-		ChatID: chatID,
-		Text:   "Fetching metadata...",
-	})
-	fetchingMsgID := 0
-	if fetchingMsg != nil {
-		fetchingMsgID = fetchingMsg.ID
-	}
-
-	// Fast playlist detection first — avoids expensive full metadata fetch for large playlists.
-	isPlaylist, plInfo, detectErr := h.YtDlp.DetectPlaylist(url)
-	if detectErr == nil && isPlaylist {
-		h.editText(ctx, chatID, fetchingMsgID, fmt.Sprintf("Playlist detected: %s (%d videos)", plInfo.Title, plInfo.PlaylistCount), nil)
-		h.handlePlaylist(ctx, chatID, userID, url, plInfo)
+	if job := h.getActiveJob(userID); job != nil {
+		h.sendText(ctx, chatID, "You already have an active download. Cancel it first.")
 		return
 	}
 
@@ -104,33 +112,33 @@ func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string,
 						{{Text: "Cancel", CallbackData: "pending_cancel"}},
 					},
 				}
-				h.editText(ctx, chatID, fetchingMsgID, "This content is DRM protected and no YouTube alternative was found automatically. Try searching by name:", &kb)
+				h.sendWithKB(ctx, chatID, "This content is DRM protected and no YouTube alternative was found automatically. Try searching by name:", kb)
 				return
 			}
-			h.editText(ctx, chatID, fetchingMsgID, fmt.Sprintf("This content is DRM protected. Found on YouTube: %s", ytTitle), nil)
+			h.sendText(ctx, chatID, fmt.Sprintf("This content is DRM protected. Found on YouTube: %s", ytTitle))
 			info, err = h.YtDlp.GetMediaInfo(youtubeURL)
 			if err != nil {
-				h.editText(ctx, chatID, fetchingMsgID, fmt.Sprintf("YouTube fallback failed: %s", err.Error()), nil)
+				h.sendText(ctx, chatID, fmt.Sprintf("YouTube fallback failed: %s", err.Error()))
 				return
 			}
 			url = youtubeURL
 		} else {
 			switch {
 			case strings.Contains(errMsg, "Unsupported URL") || strings.Contains(errMsg, "is not a valid URL"):
-				h.editText(ctx, chatID, fetchingMsgID, "This URL is not supported.", nil)
+				h.sendText(ctx, chatID, "This URL is not supported.")
 			case strings.Contains(errMsg, "HTTP Error 403") || strings.Contains(errMsg, "cookies"):
-				h.editText(ctx, chatID, fetchingMsgID, "This content requires authentication (cookies).", nil)
+				h.sendText(ctx, chatID, "This content requires authentication (cookies).")
 			case strings.Contains(errMsg, "live"):
-				h.editText(ctx, chatID, fetchingMsgID, "Cannot download live streams.", nil)
+				h.sendText(ctx, chatID, "Cannot download live streams.")
 			default:
-				h.editText(ctx, chatID, fetchingMsgID, fmt.Sprintf("Error: %s", errMsg), nil)
+				h.sendText(ctx, chatID, fmt.Sprintf("Error: %s", errMsg))
 			}
 			return
 		}
 	}
 
 	if len(info.Formats) == 0 {
-		h.editText(ctx, chatID, fetchingMsgID, "No formats available for this URL.", nil)
+		h.sendText(ctx, chatID, "No formats available for this URL.")
 		return
 	}
 
@@ -141,9 +149,9 @@ func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string,
 		if (q.DailyLimitMB > 0 && q.DailyUsedMB >= q.DailyLimitMB) ||
 			(q.WeeklyLimitMB > 0 && q.WeeklyUsedMB >= q.WeeklyLimitMB) ||
 			(q.MonthlyLimitMB > 0 && q.MonthlyUsedMB >= q.MonthlyLimitMB) {
-			h.editText(ctx, chatID, fetchingMsgID, fmt.Sprintf(
+			h.sendText(ctx, chatID, fmt.Sprintf(
 				"Quota exceeded. Daily: %d/%d MB, Weekly: %d/%d MB, Monthly: %d/%d MB.",
-				q.DailyUsedMB, q.DailyLimitMB, q.WeeklyUsedMB, q.WeeklyLimitMB, q.MonthlyUsedMB, q.MonthlyLimitMB), nil)
+				q.DailyUsedMB, q.DailyLimitMB, q.WeeklyUsedMB, q.WeeklyLimitMB, q.MonthlyUsedMB, q.MonthlyLimitMB))
 			return
 		}
 	}
@@ -173,7 +181,7 @@ func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string,
 		}
 	}
 	kb := formatKeyboard("format_", labels, ss.FormatIDs)
-	h.editText(ctx, chatID, fetchingMsgID, "Select format:", &kb)
+	h.sendWithKB(ctx, chatID, "Select format:", kb)
 }
 
 // handleFormatSelection processes a format pick from the unified list.