Let Compare and Equals treat float noise as equal numbers

A graph that checks "time - late == 6" after On timer (#224) failed,
because the difference comes out as 5.999999999999972. Both values are
sums of measured frame times, and they round along different paths.
The only workaround was a Round node in front of every comparison.

- New helper nearlyEqual in values.ts. Two numbers count as equal when
  |a - b| <= 1e-9 * max(1, |a|, |b|). The tolerance grows with the
  size of the values, so it holds for hours of summed dt.
- Compare uses the rule for all six operators. "<" and ">" only hold
  when the values are not nearly equal, "<=" and ">=" also hold when
  they are. So "==" and ">" are never true at the same time.
- Equals uses the same rule when both inputs are real numbers. Objects
  still compare by identity, everything else as text. The node
  description says so.
- The tolerance is fixed, there is no parameter on the node. Physics
  values come from float32 in Rapier and are not covered on purpose.
- The log display is unchanged and still prints the raw number.

Tests:
- ./check.sh: 156 files, 2311 tests, CHECK EXIT 0 (before 2300).
- 11 new cases in node-catalog.test.ts, including the value from the
  log against 6, growth with magnitude, 6.001 != 6 and 1e-6 > 0.
- Counter-check exact compare: exactly the 8 noise cases fail.
- Counter-check "<"/">" without the exclusion: exactly 2 cases fail.
- No e2e change, the check sum stays at 1374.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/graph/values.ts

@@ -25,6 +25,16 @@ export function isEntity(value: Value | undefined): value is EntityHandle {
   return typeof value === 'object' && value !== null && ENTITY_HANDLE in value;
 }
 
+/**
+ * Whether two numbers are the same up to float noise (#224): a relative 1e-9, never less than 1e-9
+ * absolute. `time - late` lands 1e-14 off a whole second, and after hours of summed `dt` the error
+ * still stays far below this, while 6 and 6.001 remain apart.
+ */
+export function nearlyEqual(a: number, b: number): boolean {
+  if (a === b) return true;
+  return Math.abs(a - b) <= 1e-9 * Math.max(1, Math.abs(a), Math.abs(b));
+}
+
 /** A list of anything a data edge carries – a handle among the items is what `isList` cannot say. */
 function isValueList(value: Value | undefined): value is ValueList {
   return Array.isArray(value);