v1.0.34 — Amber login: correct URL from source + clipboard/paste flow

- Read Amber's actual IntentUtils.kt source to confirm exact URL format
- Correct: nostrsigner:?type=get_public_key&compressionType=none&returnType=signature
- No callbackUrl = Amber copies pubkey to clipboard (reliable on all Android)
- On return: auto-read clipboard (hex or npub), fallback to paste input
- Accepts both hex pubkey and npub1 format from Amber