feat(electrum): add custom authentication support via ConfigBuilder

[EddieHouston]

Description

This PR enables connections to Electrum servers behind API gateways that require authentication (e.g., JWT tokens, Bearer tokens, API keys, Basic auth, or custom authorization schemes).

What's being added:

• New BdkElectrumClient::from_config() constructor that accepts custom Config for authorization and other settings

Notes to the reviewers

• Dependency: This PR requires authorization provider support from rust-electrum-client. The feature is not yet in the published 0.24.0 release. Options:

  • Merge this PR after the rust-electrum-client PR is merged and released
  • See [rust-electrum-client PR https://github.com/feat: add dynamic authorization support via callback provider rust-electrum-client#194] for the upstream changes

• This feature exposes the existing authorization capability from electrum-client through a new convenience constructor

• The from_config() method is only implemented for BdkElectrumClient<electrum_client::Client> (not the generic ElectrumApi trait) since it needs to construct a concrete client

Changelog notice

Added:

• Custom authorization support for Electrum connections via BdkElectrumClient::from_config()

Checklists

All Submissions:

• I followed the contribution guidelines

New Features:

• I've added tests for the new feature (example implementation with documented usage)
• I've added docs for the new feature (module docs, rustdoc examples, and usage guide)

Bugfixes:

• This pull request breaks the existing API
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR

[evanlinjin]

NACK

This is a lot of description/documentation for a "convenient method" which saves 1 line of code.

[EddieHouston]

NACK

This is a lot of description/documentation for a "convenient method" which saves 1 line of code.

Good feedback, I trimmed the noise down.

[evanlinjin]

@EddieHouston this PR has nothing to do with using electrum behind gateways which require authentication.

This is adding a convenience method that saves one line of code. I'm not sure I see the value of this?

[EddieHouston]

this PR has nothing to do with using electrum behind gateways which require authentication.

This is adding a convenience method that saves one line of code. I'm not sure I see the value of this?

Reasonable point, guess the value was the idea of helping people find out that using auth was possible. But you are right... and I don't see any other places this is done in the codebase.

I'll just focus on bitcoindevkit/rust-electrum-client#194 and if needed perhaps later we could add something to the example_electrum to show auth usage if it makes sense.

Thanks for your feedback and time 👍