maude: run.sx search command + result-sort output (254 total)

run.sx now handles 'search START =>* GOAL .' (reports the witness path) and
mau/run-pretty prints Maude-style 'result SORT: TERM' using least-sort
inference. searchpath.sx exposes mau/search-path-terms (term-level entry).

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

plans/maude-on-sx.md

@@ -108,7 +108,9 @@ The novel substrate stress: equational matching. Pattern `X + Y` against `1 + 2
 - [x] Program runner (`lib/maude/run.sx`) — `mau/run-program` / `mau/run` parse
   a module plus trailing `reduce`/`red`/`rewrite`/`rew TERM .` commands
   (`... in MOD : TERM` qualifier accepted) and execute them, rendering results
-  in surface syntax. Runs an idiomatic `.maude` file end-to-end. 6 tests.
+  in surface syntax. Runs an idiomatic `.maude` file end-to-end. Now also:
+  `search START =>* GOAL .` command (reports the path), least-sort annotated
+  output via `mau/run-pretty` → `result SORT: TERM` (Maude-style). 10 tests.
 - [x] Witness-path search (`lib/maude/searchpath.sx`) — `mau/search-path` /
   `mau/search-length` return the shortest sequence of states start..goal (the
   solution moves), not just yes/no. 8 tests.