ocaml: phase 1+2 records {x=1;y=2} + with-update (+6 tests, 289 total)

Parser: { f = e; f = e; ... } -> (:record (F E)...). { base with f = e;
... } -> (:record-update BASE (F E)...). Eval builds a dict from field
bindings; record-update merges the new fields over the base dict — the
same dict representation already used for modules.

{ also added to at-app-start? so records are valid arg atoms. Field
access via the existing :field postfix unifies record/module access.

Record patterns deferred to a later iteration.

lib/ocaml/test.sh

@@ -714,6 +714,20 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 1004)
 (eval "(ocaml-run-program \"let g _ x = x + 1;; g 99 41\")")
 
+;; ── Records ────────────────────────────────────────────────────
+(epoch 1100)
+(eval "(ocaml-run \"let r = { x = 1; y = 2 } in r.x\")")
+(epoch 1101)
+(eval "(ocaml-run \"let r = { x = 1; y = 2 } in r.x + r.y\")")
+(epoch 1102)
+(eval "(ocaml-run \"let r = { x = 1; y = 2 } in let r2 = { r with x = 99 } in r2.x + r2.y\")")
+(epoch 1103)
+(eval "(ocaml-run \"let p = { name = \\\"Bob\\\"; age = 30 } in p.name\")")
+(epoch 1104)
+(eval "(ocaml-run \"let p = { name = \\\"Bob\\\"; age = 30 } in p.age\")")
+(epoch 1105)
+(eval "(ocaml-run-program \"let r = { x = 1; y = 2 };; r.x + r.y\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 180 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1131,6 +1145,14 @@ check 1002 "let f _ = 1 in f 5"           '1'
 check 1003 "top-level let f () ="         '7'
 check 1004 "wildcard top-level"           '42'
 
+# ── Records ─────────────────────────────────────────────────────
+check 1100 "record literal + access"      '1'
+check 1101 "record sum fields"            '3'
+check 1102 "record with-update"           '101'
+check 1103 "record string field"          '"Bob"'
+check 1104 "record int field"             '30'
+check 1105 "top-level record decl"        '3'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL OCaml-on-SX tests passed"