ocaml: phase 6 Float module fleshed out (+6 tests, 598 total)

New Float members:
  zero / one / minus_one
  abs / neg
  add / sub / mul / div     (lift host '+.' '-.' '*.' '/.')
  max / min                 (if-based)
  equal / compare           (Float.compare returns -1 / 0 / 1)
  to_int                    (host floor)
  of_int                    (identity in dynamic runtime)
  of_string                 (delegates to _int_of_string)

Aligns Float with Int's API and lets baselines use Float.add /
Float.compare / etc without lifting the symbols themselves.

  Float.add 3.5 4.5         = 8
  Float.compare 2.5 5.0     = -1
  Float.abs -3.7            = 3.7
  Float.max 3.14 2.71       = 3.14

lib/ocaml/test.sh

@@ -1480,6 +1480,20 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 5232)
 (eval "(ocaml-run \"Result.compare compare compare (Ok 1) (Error \\\"fail\\\")\")")
 
+;; ── Float module additions ───────────────────────────────────
+(epoch 5240)
+(eval "(ocaml-run \"Float.add 3.5 4.5\")")
+(epoch 5241)
+(eval "(ocaml-run \"Float.compare 2.5 5.0\")")
+(epoch 5242)
+(eval "(ocaml-run \"Float.abs (-3.7)\")")
+(epoch 5243)
+(eval "(ocaml-run \"Float.max 3.14 2.71\")")
+(epoch 5244)
+(eval "(ocaml-run \"Float.equal 1.5 1.5\")")
+(epoch 5245)
+(eval "(ocaml-run \"Float.zero +. Float.one\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 360 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -2354,6 +2368,14 @@ check 5230 "Result.equal Ok 1 Ok 1"       'true'
 check 5231 "Result.compare Ok 5 Ok 3"     '1'
 check 5232 "Result.compare Ok < Error"    '-1'
 
+# ── Float module additions ──────────────────────────────────────
+check 5240 "Float.add 3.5 4.5"            '8'
+check 5241 "Float.compare 2.5 5.0"        '-1'
+check 5242 "Float.abs -3.7"               '3.7'
+check 5243 "Float.max 3.14 2.71"          '3.14'
+check 5244 "Float.equal 1.5 1.5"          'true'
+check 5245 "Float.zero +. Float.one"      '1'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL OCaml-on-SX tests passed"