test: prove the android pubky marketplace wallet leg

[ovitrif]

Parent: #1207
Source: Pubky marketplace Bitkit team brief
Counterpart: synonymdev/bitkit-ios#718

Scope

• Exercise the existing pubkyauth deep link, watch-only consent and xpub claim, linked-contact prerequisite, incoming Payment Request, payment approval, and regtest confirmation.
• Record the first shipped release or tag containing the claim and incoming-request surfaces.
• Add the matching journey with identifiers aligned to iOS.
• Run the journey against the current implementation first so it establishes the baseline and exposes remaining gaps.

Acceptance criteria

• The full flow passes end to end on Android.
• Any discovered code gap is tracked as a blocking subissue.