maude: Phase 2 syntactic equational reduction (26 tests, 91 total)

lib/maude/reduce.sx — one-sided syntactic matching (non-linear patterns
via bound-var equality), immutable substitutions, innermost fixpoint
normalisation. Tested on Peano arithmetic, list ops, a propositional
logic simplifier, and non-linear matching.

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

lib/maude/conformance.conf

@@ -8,8 +8,10 @@ PRELOADS=(
   lib/guest/pratt.sx
   lib/maude/term.sx
   lib/maude/parser.sx
+  lib/maude/reduce.sx
 )
 
 SUITES=(
   "parse:lib/maude/tests/parse.sx:(mau-parse-tests-run!)"
+  "reduce:lib/maude/tests/reduce.sx:(mau-reduce-tests-run!)"
 )