draw/drawfcall/mux_plan9.go compile errors

[yrk-lab]

term% go version
go version go1.25.6 plan9/arm
term% go install 9fans.net/go/acme/Watch@main
# 9fans.net/go/draw/drawfcall
go/pkg/mod/9fans.net/go@v0.0.8-0.20250307142834-96bdba94b63f/draw/drawfcall/mux_plan9.go:131:11: cannot use atoi(f[4]) (value of type int) as uint32 value in assignment
go/pkg/mod/9fans.net/go@v0.0.8-0.20250307142834-96bdba94b63f/draw/drawfcall/mux_plan9.go:154:35: cursor.Clr undefined (type *Cursor has no field or method Clr)
go/pkg/mod/9fans.net/go@v0.0.8-0.20250307142834-96bdba94b63f/draw/drawfcall/mux_plan9.go:154:51: cursor.Set undefined (type *Cursor has no field or method Set)
go/pkg/mod/9fans.net/go@v0.0.8-0.20250307142834-96bdba94b63f/draw/drawfcall/mux_plan9.go:160:26: cursor.Clr undefined (type *Cursor has no field or method Clr)
go/pkg/mod/9fans.net/go@v0.0.8-0.20250307142834-96bdba94b63f/draw/drawfcall/mux_plan9.go:161:26: cursor.Set undefined (type *Cursor has no field or method Set)

[mischief]

see #140