artdag: miniKanren CLP(FD) scheduler (schedule.sx) + 15 tests

lib/artdag/schedule.sx on lib/minikanren: slot var per node, fd-lt per edge, fd-label
search. schedule-asap (smallest-first labeling) agrees exactly with plan.sx greedy Kahn
waves (cross-validated); schedules enumerates all valid schedules; schedules-capped
filters to <=cap per slot; schedule-valid? independent dep check. Adds a 'schedule' suite
to conformance.sh loading the minikanren CLP(FD) stack. Completes the optional Phase 3/7
miniKanren box. schedule 15/15, total 213/213.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/artdag/conformance.sh

@@ -13,7 +13,7 @@ if [ ! -x "$SX_SERVER" ]; then
   exit 1
 fi
 
-SUITES=(dag analyze plan execute optimize fed cost serialize stats fault maude-optimize)
+SUITES=(dag analyze plan execute optimize fed cost serialize stats fault maude-optimize schedule)
 
 OUT_JSON="lib/artdag/scoreboard.json"
 OUT_MD="lib/artdag/scoreboard.md"
@@ -25,6 +25,27 @@ run_suite() {
   TMP=$(mktemp)
   local MAUDE_LOADS=""
   local BRIDGE_LOAD=""
+  local MK_LOADS=""
+  local SCHED_LOAD=""
+  if [ "$suite" = "schedule" ]; then
+    MK_LOADS='(load "lib/guest/match.sx")
+(load "lib/minikanren/unify.sx")
+(load "lib/minikanren/stream.sx")
+(load "lib/minikanren/goals.sx")
+(load "lib/minikanren/fresh.sx")
+(load "lib/minikanren/conde.sx")
+(load "lib/minikanren/run.sx")
+(load "lib/minikanren/relations.sx")
+(load "lib/minikanren/project.sx")
+(load "lib/minikanren/diseq.sx")
+(load "lib/minikanren/intarith.sx")
+(load "lib/minikanren/matche.sx")
+(load "lib/minikanren/defrel.sx")
+(load "lib/minikanren/nafc.sx")
+(load "lib/minikanren/fd.sx")
+(load "lib/minikanren/clpfd.sx")'
+    SCHED_LOAD='(load "lib/artdag/schedule.sx")'
+  fi
   if [ "$suite" = "maude-optimize" ]; then
     MAUDE_LOADS='(load "lib/guest/lex.sx")
 (load "lib/guest/pratt.sx")
@@ -64,6 +85,7 @@ run_suite() {
 (load "lib/persist/kv.sx")
 (load "lib/persist/api.sx")
 ${MAUDE_LOADS}
+${MK_LOADS}
 (load "lib/artdag/dag.sx")
 (load "lib/artdag/analyze.sx")
 (load "lib/artdag/plan.sx")
@@ -76,6 +98,7 @@ ${MAUDE_LOADS}
 (load "lib/artdag/fault.sx")
 (load "lib/artdag/api.sx")
 ${BRIDGE_LOAD}
+${SCHED_LOAD}
 (epoch 2)
 (eval "(define artdag-test-pass 0)")
 (eval "(define artdag-test-fail 0)")