search: Phase 2 query parser + 32 tests

Query tokenizer + recursive-descent parser: OR<AND<NOT precedence, implicit AND
on adjacency, quoted phrases, parens, case-insensitive keywords. parseQuery,
searchQuery, showQ. Worked around haskell-on-sx parser limits (ord-based
delimiters; multi-clause fns instead of []-pattern case alts). 78/78.

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

lib/search/conformance.conf

@@ -21,6 +21,7 @@ PRELOADS=(
   lib/search/tokenize.sx
   lib/search/index.sx
   lib/search/query.sx
+  lib/search/parse.sx
   lib/search/api.sx
   lib/search/testlib.sx
 )
@@ -28,4 +29,5 @@ PRELOADS=(
 SUITES=(
   "index:lib/search/tests/index.sx"
   "boolean:lib/search/tests/boolean.sx"
+  "parse:lib/search/tests/parse.sx"
 )