maude: Phase 6 strategy language (19 tests, 178 total)

lib/maude/strategy.sx — first-class set-valued strategies: idle/fail/all/
rule/seq/alt/star/plus/bang/name combinators, named-strategy env. Same
rule set computes different things under different strategies; verified
with single-rule vs all vs seq-order vs alt vs star vs bang.

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/strategy.sx
 )
 
 SUITES=(
@@ -21,4 +22,5 @@ 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!)"
+  "strategy:lib/maude/tests/strategy.sx:(mau-strategy-tests-run!)"
 )