fix(pglite): do not cut slow readers, and bind playlist rules as text

The bridge gave every reply write a 5 second deadline. Scanner phase 3
streams all touched albums through a cursor and runs queries per row on
other pooled connections, which queue on the single session, so a large
library could not drain the reply in time and the bridge closed the pipe
mid-message ('unexpected EOF'). Replies now block as long as the client
needs, and client connections are closed on shutdown instead.

Playlist rules were bound as []byte, which pgx sends as bytea; the text
column then stored the hex form and the JSON parser failed on it.

db/pglite/pglite.go

@@ -428,6 +428,7 @@ func (pg *PGlite) handleConn(conn net.Conn, ioBase string) {
 		defer fmt.Fprintln(pg.cfg.Stderr, "# bridge: client disconnected")
 	}
 	defer conn.Close()
+	defer context.AfterFunc(pg.ctx, func() { _ = conn.Close() })()
 	outFile := ioBase + ".out"
 	buf := make([]byte, 65536)
 
@@ -597,7 +598,8 @@ func (pg *PGlite) sendReplies(conn net.Conn, replies [][]byte) bool {
 				fmt.Fprintf(pg.cfg.Stderr, "# bridge S> raw %q\n", data)
 			}
 		}
-		_ = conn.SetWriteDeadline(time.Now().Add(5 * time.Second))
+		// No write deadline: a client may drain a large result slowly (e.g. a cursor that runs
+		// queries per row); the connection is closed on shutdown instead.
 		if _, err := conn.Write(data); err != nil {
 			return false
 		}

persistence/playlist_repository.go

@@ -33,12 +33,12 @@ func (p *dbPlaylist) PostScan() error {
 }
 
 func (p dbPlaylist) PostMapArgs(args map[string]any) error {
-	var err error
 	if p.Playlist.IsSmartPlaylist() {
-		args["rules"], err = json.Marshal(p.Playlist.Rules)
+		rules, err := json.Marshal(p.Playlist.Rules)
 		if err != nil {
 			return fmt.Errorf("invalid criteria expression: %w", err)
 		}
+		args["rules"] = string(rules) // []byte would be bound as bytea and stored as its hex form
 		// Smart playlist counters are owned by refreshCounters (evaluation), never by callers
 		delete(args, "song_count")
 		delete(args, "duration")