maude: witness-path search for puzzle solvers (8 tests, 221 total)

lib/maude/searchpath.sx — mau/search-path returns the shortest sequence of
states from start to goal (the solution moves), mau/search-length its step
count. BFS over all one-step successors, threading the path.

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

lib/maude/conformance.conf

@@ -13,6 +13,7 @@ PRELOADS=(
   lib/maude/conditional.sx
   lib/maude/fire.sx
   lib/maude/rewrite.sx
+  lib/maude/searchpath.sx
   lib/maude/strategy.sx
   lib/maude/meta.sx
   lib/maude/pretty.sx
@@ -25,6 +26,7 @@ SUITES=(
   "matching:lib/maude/tests/matching.sx:(mau-matching-tests-run!)"
   "conditional:lib/maude/tests/conditional.sx:(mau-conditional-tests-run!)"
   "rewrite:lib/maude/tests/rewrite.sx:(mau-rewrite-tests-run!)"
+  "searchpath:lib/maude/tests/searchpath.sx:(mau-searchpath-tests-run!)"
   "strategy:lib/maude/tests/strategy.sx:(mau-strategy-tests-run!)"
   "meta:lib/maude/tests/meta.sx:(mau-meta-tests-run!)"
   "pretty:lib/maude/tests/pretty.sx:(mau-pretty-tests-run!)"