Differentiate distribution method on specific recipients

Feature Description

Allow API-created envelopes to specify the distribution method per-recipient. The current behaviour specifies the distribution method at envelope level, and that is shared by all recipients. For mobile app embedded workflows, this may be a limiting factor.

Use Case

A document must be signed by two classes of signer:

• Approving signer - whoever takes responsibility for the document's content in case of dispute, e.g. customer, plant manager, function manager. Requires (at least weak) authentication, e.g. 2FA via e-mail OTP.
• Document owner - can sign directly in-app while generating the document, via an embedded browser that redirects to the Documenso-generated link.

This affects digitalized workflows that require document signing, e.g. B2B field service.

Proposed Solution

Add a distributionMethod field to payload.recipients on POST /envelope/create that overrides the envelope-defined distribution method for a specific recipient.

Alternatives (optional)

No response

Additional Context

No response

Please check the boxes that apply to this feature request.

• I have searched the existing feature requests to make sure this is not a duplicate.
• I have provided a detailed description of the requested feature.
• I have explained the use case or scenario for this feature.
• I have included any relevant technical details or design suggestions.
• I understand that this is a suggestion and that there is no guarantee of implementation.