feat: add btcpay wallet connection

[ben-kaufman]

Description

This PR:

1. Adds Android support for connecting a BTCPay store from setup links.
2. Shares a Bitcoin on-chain receive descriptor from BitkitCore using the wallet's current primary address type.
3. Routes setup links from scanner, paste, gallery scan, scanner sheet, and deeplink entry points into the same connection flow.
4. Adds the BTCPay connection sheet, setup-link validation, redacted logging, and regression coverage for the new flow.

Preview

bitkit-btcpay-samrock-android-e2e-proof-20260521.webm

QA Notes

Manual Tests

• 1. BTCPay setup QR → Android Bitkit setup link: BTCPay connection sheet opens with the store and Bitcoin on-chain descriptor sharing.
• 2. Bitkit Android connection sheet → Connect → Receive: connection succeeds and Receive shows an on-chain address.
• 3. BTCPay wallet address list → filter derived addresses: BTCPay shows the same address as Bitkit Receive.
• 4. regression: Scanner/paste/deeplink setup links → unsupported or invalid setup links: setup errors show without opening the send flow.

Automated Checks

• Unit tests added: cover setup-link parsing, response parsing, descriptor registration, launch-key redaction, and scan/deeplink routing.
• Android instrumentation compile coverage updated for BitkitCore 0.1.60 descriptor generation.
• ./gradlew compileDevDebugKotlin
• ./gradlew testDevDebugUnitTest
• ./gradlew detekt
• E2E=true GEO=false ./gradlew assembleDevDebug