fix: expose rejected incoming payment requests

[ovitrif]

Parent: #712
Source: Pubky marketplace Bitkit team brief
Counterpart: synonymdev/bitkit-android#1209

Scope

• Replace silent parse-time drops with redacted, reason-specific diagnostics.
• Define and implement user feedback for requested/open-time failures after the retry policy is exhausted.
• Preserve background retry behavior for transient automatic presentation failures.

Acceptance criteria

• Malformed and unresolvable requests are distinguishable in logs.
• A user explicitly opening a request receives a localized terminal result.
• Tests cover parse and resolution failures.