Implement core clustering logic and scoring features

This update introduces the core clustering algorithm, including parallel execution, dynamic block sizing, and SIMD-accelerated scoring methods. It also adds robust sequence preparation, k-mer analysis, and comprehensive test data fixtures for validation.

pkg/obialign/lcsband_nosimd.go

@@ -11,3 +11,7 @@ func encodeBases(ws *bandedLCSWorkspace, a, b []byte) {}
 func bandedLCSSIMD(lA, lB, kmin, kmax int, ws *bandedLCSWorkspace) uint32 {
 	return 0
 }
+
+func lcsScoreSIMD(a, b []byte, kmin, kmax, minLCS int, ws *bandedLCSWorkspace) int {
+	return -1
+}