Add Fix My Playlist feature

New endpoint POST /api/playlists/{id}/fix that analyzes a playlist
using Claude AI to identify outlier tracks that don't match the
overall vibe, and suggests better-fitting replacements.

Frontend shows results with warm amber cards for outliers and green
cards for replacements, with dismissible suggestions and visual
highlighting of flagged tracks in the track list.

frontend/src/lib/api.ts

@@ -97,6 +97,7 @@ export interface RecommendationItem {
   image_url: string | null
   spotify_url: string | null
   bandcamp_url: string | null
+  youtube_url: string | null
   reason: string
   saved: boolean
   disliked: boolean
@@ -175,6 +176,7 @@ export const generateRecommendations = (
   mode?: string,
   adventurousness?: number,
   exclude?: string,
+  count?: number,
 ) =>
   api.post<RecommendationResponse>('/recommendations/generate', {
     playlist_id: playlistId,
@@ -183,6 +185,7 @@ export const generateRecommendations = (
     mode: mode || 'discover',
     adventurousness: adventurousness ?? 3,
     exclude: exclude || undefined,
+    count: count ?? 5,
   }).then((r) => r.data)
 
 export const getRecommendationHistory = () =>
@@ -278,6 +281,30 @@ export async function getBandcampEmbed(url: string): Promise<BandcampEmbed> {
   return data
 }
 
+// Playlist Fix
+export interface OutlierTrack {
+  track_number: number
+  artist: string
+  title: string
+  reason: string
+}
+
+export interface ReplacementTrack {
+  title: string
+  artist: string
+  album: string | null
+  reason: string
+}
+
+export interface PlaylistFixResponse {
+  playlist_vibe: string
+  outliers: OutlierTrack[]
+  replacements: ReplacementTrack[]
+}
+
+export const fixPlaylist = (playlistId: string) =>
+  api.post<PlaylistFixResponse>(`/playlists/${playlistId}/fix`).then((r) => r.data)
+
 // Taste Profile
 export const getTasteProfile = () =>
   api.get<TasteProfileResponse>('/profile/taste').then((r) => r.data)