feat: add overlap studies wrappers and align indicator API names

- add TA-Lib bindings and loader registrations for overlap studies:
  TA_ACCBANDS, TA_BBANDS, TA_DEMA, TA_EMA, TA_HT_TRENDLINE, TA_KAMA
- add new public wrappers in overlap_studies.go:
  AccBands, BBands, DEMA, EMA, HT_TRENDLINE, KAMA
- refactor momentum wrapper names to consistent Go-style exports
  (e.g. Aroon/AroonOsc, MACDExt/MACDFix, Stoch/StochF/StochRSI,
  MinusDI/MinusDM, PlusDI/PlusDM, Trix, UltOsc, WillR)
- rename MAType constants to MA_* for clearer namespacing
- update README to reflect the current exported API and overlap coverage

functions.go

@@ -670,4 +670,72 @@ var (
 		outNBElement *int32,
 		outReal []float64,
 	) int32
+
+	accbands func(
+		startIdx int32,
+		endIdx int32,
+		inHigh []float64,
+		inLow []float64,
+		inClose []float64,
+		optInTimePeriod int32,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outUpperBand []float64,
+		outMiddleBand []float64,
+		outLowerBand []float64,
+	) int32
+
+	bbands func(
+		startIdx int32,
+		endIdx int32,
+		inReal []float64,
+		optInTimePeriod int32,
+		optInNbDevUp float64,
+		optInNbDevDn float64,
+		optInMAType int32,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outUpperBand []float64,
+		outMiddleBand []float64,
+		outLowerBand []float64,
+	) int32
+
+	dema func(
+		startIdx int32,
+		endIdx int32,
+		inReal []float64,
+		optInTimePeriod int32,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outReal []float64,
+	) int32
+
+	ema func(
+		startIdx int32,
+		endIdx int32,
+		inReal []float64,
+		optInTimePeriod int32,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outReal []float64,
+	) int32
+
+	ht_trendline func(
+		startIdx int32,
+		endIdx int32,
+		inReal []float64,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outReal []float64,
+	) int32
+
+	kama func(
+		startIdx int32,
+		endIdx int32,
+		inReal []float64,
+		optInTimePeriod int32,
+		outBegIdx *int32,
+		outNBElement *int32,
+		outReal []float64,
+	) int32
 )