Folding nfc into a static render suite needs a dispatch mechanism #77

The TF discussion on #54 converged on three broad suites: static (pre-baked artifacts), data (card object), and html. The spec currently keeps nfc as its own renderSuite value instead of folding it into static, because of a gap:

The nfc suite value tells the wallet what to do with the payload -- transmit it over an NFC radio, not display it. If NFC payloads, images, and PDFs all share renderSuite: "static", nothing else in the render method carries that distinction:

1. template.mediaType does not work: the NFC example uses application/octet-stream, and there is no well-known registered media type that means "NDEF/NFC payload".
2. outputPreference.accessMode (visual, auditory, tactile, textual) describes how a human perceives the rendering, not a machine transmission channel.

Some options include:

• Keep nfc (and similar channel-specific methods) as their own suite values, reserving static for artifacts the wallet displays directly (current state of the spec).
• Fold them into static and add a discriminator property (e.g. a channel or delivery hint).
• Fold them into static and mint/register a dedicated media type for NFC payloads.