ocaml: phase 1 unit/wildcard params + 180s timeout (+5 tests, 283 total)

Parser: try-consume-param! handles ident, wildcard _ (fresh __wild_N
name), unit () (fresh __unit_N), typed (x : T) (skips signature).
parse-fun and parse-let (inline) reuse the helper; top-level
parse-decl-let inlines a similar test.

test.sh timeout bumped from 60s to 180s — the growing suite was hitting
the cap and reporting spurious failures.

lib/ocaml/test.sh

@@ -702,9 +702,21 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 974)
 (eval "(ocaml-run \"Int.min 7 3\")")
 
+;; ── Unit / wildcard parameters ──────────────────────────────────
+(epoch 1000)
+(eval "(ocaml-run \"let f () = 42 in f ()\")")
+(epoch 1001)
+(eval "(ocaml-run \"(fun () -> 99) ()\")")
+(epoch 1002)
+(eval "(ocaml-run \"let f _ = 1 in f 5\")")
+(epoch 1003)
+(eval "(ocaml-run-program \"let f () = 7;; f ()\")")
+(epoch 1004)
+(eval "(ocaml-run-program \"let g _ x = x + 1;; g 99 41\")")
+
 EPOCHS
 
-OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
+OUTPUT=$(timeout 180 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
 
 check() {
   local epoch="$1" desc="$2" expected="$3"
@@ -1112,6 +1124,13 @@ check 972 "Int.abs -5"                   '5'
 check 973 "Int.max"                      '7'
 check 974 "Int.min"                      '3'
 
+# ── Unit / wildcard parameters ──────────────────────────────────
+check 1000 "let f () = 42 in f ()"        '42'
+check 1001 "(fun () -> 99) ()"            '99'
+check 1002 "let f _ = 1 in f 5"           '1'
+check 1003 "top-level let f () ="         '7'
+check 1004 "wildcard top-level"           '42'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL OCaml-on-SX tests passed"