wip(tracks): phase 5 - a print names its maker, and a read print points at the next one (the chain); goes with maroon-lake phase-5

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.tracks/system.ludic

@@ -4,6 +4,7 @@ export function tracks_reset(tracks_st: mut TracksState) -> void {
   tracks_st.tk_read_n = 0
   tracks_st.tk_yaw = 0.0
   tracks_st.tk_has_yaw = false
+  tracks_st.tk_chain = -1
   q_clear(tracks_reads(tracks_st))
 }