P5: track index.d.ts + reject invalid periods in the Node binding (#83)

* build(node): track the generated index.d.ts (P5.1)

index.js was committed but index.d.ts was gitignored, an inconsistency that
also contradicts CONTRIBUTING ('regenerate both .d.ts/.js when a binding API
changes'). Track index.d.ts too so the repo carries the TypeScript types as a
matched pair with index.js. Generated by napi build; ~214 indicator classes.

* fix(node): reject invalid periods instead of clamping them (P5.4)

The Node scalar-indicator macro clamped period 0 to 1 (via clamp_period + must)
and the multi-parameter constructors did the same, silently swallowing the
core's PeriodZero validation. The core rejects period 0 (Error::PeriodZero),
and the Python and WASM bindings already propagate it — Node was the outlier,
masking caller mistakes. Make the macro constructor fallible and let every
constructor propagate the core error via map_err, removing clamp_period/must.
Update the smoke test (period 0 now throws, matching core/Python/WASM).

* docs(changelog): note the Node period-validation change (P5.4)

Behavior change per CONTRIBUTING: Node constructors now reject invalid periods
instead of clamping. Add an [Unreleased] Changed entry.

* chore: drop accidentally committed scratch log

bindings/node/__tests__/smoke.test.js

@@ -73,10 +73,10 @@ test('ATR batch shape', () => {
   }
 });
 
-test('zero period is clamped to a valid window', () => {
-  // Constructors cannot throw from JS (napi-rs 2.16 limitation), so they
-  // clamp pathological values like period=0 to the smallest valid window.
-  const sma = new wickra.SMA(0);
-  assert.equal(sma.warmupPeriod(), 1);
-  assert.equal(sma.update(42), 42);
+test('zero period is rejected at construction', () => {
+  // The core rejects period 0 (Error::PeriodZero); the Node binding propagates
+  // it as a thrown JS error, consistent with the Python and WASM bindings.
+  assert.throws(() => new wickra.SMA(0), /period must be greater than zero/);
+  // A valid period still constructs and runs.
+  assert.equal(new wickra.SMA(1).update(42), 42);
 });