fix: remove implicit bitcoinjs require from DescriptorsFactory

[Kukks]

Summary

• Removes the lazy require('./adapters/bitcoinjs') fallback from DescriptorsFactory that caused bundler failures when bitcoinjs-lib is not installed
• DescriptorsFactory now requires an explicit BitcoinLib backend adapter (createBitcoinjsLib(ecc) or createScureLib()) instead of accepting a raw TinySecp256k1Interface
• The convenience packages (@bitcoinerlab/descriptors, @bitcoinerlab/descriptors-scure) already use explicit adapters and are unaffected

Problem

The require('./adapters/bitcoinjs') in DescriptorsFactory creates a static dependency chain:

descriptors.ts → require('./adapters/bitcoinjs') → import 'bitcoinjs-lib'

Bundlers like esbuild (Cloudflare Wrangler), Webpack, and Metro resolve this chain statically — even inside try/catch blocks — causing build failures when bitcoinjs-lib is not installed. This affects consumers who only use the scure backend.

Converting require() to import() does not help because with "module": "commonjs" in tsconfig, TypeScript compiles import() to Promise.resolve().then(() => require(...)), which bundlers still follow (as documented in ledger.ts lines 70-81).

Solution

Remove the implicit fallback entirely. Consumers must now explicitly choose their backend:

// Before (broken with bundlers when bitcoinjs-lib is not installed):
DescriptorsFactory(ecc);

// After:
import { createBitcoinjsLib } from '@bitcoinerlab/descriptors-core/bitcoinjs';
DescriptorsFactory(createBitcoinjsLib(ecc));

// Or:
import { createScureLib } from '@bitcoinerlab/descriptors-core/scure';
DescriptorsFactory(createScureLib());

This is a minor breaking change for consumers who used the implicit DescriptorsFactory(ecc) shorthand directly on descriptors-core. The convenience wrapper packages are unaffected since they already pass pre-built adapters.

Note on remaining require() calls

The other require() calls in the codebase (psbt.ts, keyInterfaces.ts, signers.ts, ledger.ts) resolve to internal adapter files that are always present in the package, so they don't cause bundler failures. The ledger.ts require('@ledgerhq/ledger-bitcoin') is only reached when consumers explicitly use Ledger functionality.

Ref: #66

[landabaso]

Thanks for the PR. I have an alternative non-breaking fix that will be merged today, @Kukks. I'd like to verify it doesn't affect downstream dependents before proceeding further.

[landabaso]

Thanks again! Closed in favour of #68 .

Published as @bitcoinerlab/descriptors@3.1.7.