Implement Fingerprint Extraction from BIP380 descriptors

[cc-unchained]

Summary

Implement fingerprint extraction from BIP380 descriptors

This change adds a new function getFingerprintFromBip380Descriptor to extract the master key fingerprint from BIP380 descriptor strings. The function parses the key origin information (enclosed in square brackets) and returns the fingerprint as a lowercase hex string.

Key Changes

• New function: getFingerprintFromBip380Descriptor(descriptor: string): string | null

• Uses regex pattern to match [fingerprint]/ format

• Returns fingerprint in lowercase hex or null if not found

• Handles both uppercase and lowercase input

• Comprehensive tests covering:

• wpkh descriptors with key origin

• sh(wpkh) descriptors with key origin

• Descriptors without key origin (returns null)

• Invalid descriptors (returns null)

• Case normalization to lowercase

Usage

const descriptor = "wpkh([d34db33f/44'/0'/0']xpub.../1/*)";
const fingerprint = getFingerprintFromBip380Descriptor(descriptor);
// Returns: "d34db33f"

This enhancement improves compatibility with BIP380 standards and provides
convenient access to fingerprint information for wallet management and key
identification.

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🦋 Changeset detected

Latest commit: d69b9ea

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@caravan/descriptors	Patch

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