feat: add search filter bar to playlist detail and favorites views

styles.css

@@ -718,6 +718,11 @@ nav{flex:1;overflow-y:auto;padding:4px 10px}
 .sort-chip{padding:6px 14px;background:var(--surface);border:1px solid var(--border2);border-radius:20px;font-size:12px;font-weight:600;cursor:pointer;white-space:nowrap;color:var(--text2);font-family:var(--font);transition:border-color .15s,color .15s,background .15s}
 .sort-chip:hover{border-color:var(--accent);color:var(--accent)}
 .sort-chip.active{background:var(--accent);border-color:var(--accent);color:#000}
+.list-search-wrap{position:relative;margin-bottom:12px}
+.list-search-wrap svg{position:absolute;left:10px;top:50%;transform:translateY(-50%);color:var(--text3);pointer-events:none}
+.list-search{width:100%;box-sizing:border-box;padding:8px 12px 8px 32px;background:var(--surface);border:1px solid var(--border2);border-radius:8px;color:var(--text1);font-size:13px;font-family:var(--font);outline:none;transition:border-color .15s}
+.list-search:focus{border-color:var(--accent)}
+.list-search::placeholder{color:var(--text3)}
 .topsong-item{display:grid;grid-template-columns:28px 44px 1fr auto;align-items:center;gap:10px;padding:7px 10px;border-radius:8px;cursor:pointer;transition:background .15s}
 .topsong-item:hover{background:var(--surface)}
 .topsong-num{font-size:11px;color:var(--text3);font-family:var(--mono);text-align:center}