lib/sort: faithful search + lbisect + rbisect port

Ports ref/hare/sort/{search,bisect}.ha and the cmpfunc type
(types.ha), replacing the experimental vtable placeholder. The
powersort sort()/shuffle() surface stays out of scope.

Divergences forced by ww's surface (rule-10 align-down, not
behavioural):
  - cmp is a fn-VALUE param (cmpfunc), not Hare's *cmpfunc: ww
    renders functions-in-an-interface by value, as lib/io.ww's
    stream vtable does; *cmpfunc is not callable (no fn-ptr
    auto-deref) and &fn is *fn(...), unassignable to the alias.
  - no const (ww has none); *u8 base + uintptr stride (no [*]
    unbounded array, per 962); len() is i32 so cast : size;
    single-condition for, so Hare's afterthought is a body tail.
  - merged into one sort.ww (ww per-module convention; 900_stdlib
    smoke-compiles the file standalone, which a split breaks).

963_sort_run exercises all three on a []i32 with a real cmpfunc,
mirroring +test.ha's search/lbisect/rbisect @test fns. The
comparator binds its derefs to locals to dodge the pre-existing
inline-deref-in-comparison cgen bug (#116); that bug is in the
user comparator, not search/bisect, so the port is faithful.

lib/sort is not compiler-imported: byte-id-neutral, no combined.ww
change, 990-997 unaffected.

Makefile

@@ -340,6 +340,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_opaque_decl_run \
 	  $(BIN)/test_opaque_guards \
 	  $(BIN)/test_opaque_assign_cast_run \
+	  $(BIN)/test_sort_run \
 	  $(BIN)/test_bufio_run $(BIN)/test_random_run
 
 $(BIN)/test_smoke: test/wcc/000_smoke.c $(LIB)/libwcc.a | $(BIN)
@@ -1113,6 +1114,10 @@ $(BIN)/test_opaque_assign_cast_run: test/wcc/962_opaque_assign_cast_run.c \
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+$(BIN)/test_sort_run: test/wcc/963_sort_run.c $(BIN)/ww \
+		$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l $(LIB)/libwwrt.a | $(BIN)
+	$(CC) $(CFLAGS) -o $@ $<
+
 $(BIN)/test_f64crossmod_run: test/wcc/953_f64crossmod_run.c $(BIN)/ww \
 		$(BIN)/w6c $(BIN)/w6c_ww $(BIN)/w6a $(BIN)/w6l \
 		$(LIB)/libwwrt.a | $(BIN)