NfcTagEmulation

The share URL this phone is currently offering to NFC readers, as an encoded NDEF message.

Card emulation is served by the system, in a service this app does not own the lifetime of, so the armed payload lives here rather than in the service. Nothing is offered unless a share surface has armed it: a reader that taps an unarmed phone gets no tag at all. Channel URLs carry channel PSKs, so "armed only while the share dialog is open" is the privacy boundary, the same exposure as the QR code being on screen.