fix(ios): deliver tag when NDEF probe fails instead of dropping discovery

[apartx]

Problem

On iOS, convert(_ value: NFCNDEFTag, ...) performs an NDEF probe (queryNDEFStatus → readNDEF) immediately after the tag connects. If either step fails, it calls completionHandler(nil, error), which propagates as a failed connect — so the Dart onDiscovered callback never fires and the discovery is silently lost.

This breaks tags that are perfectly usable over their type-specific interface but return a transient error from the NDEF probe. In particular, NTAG21x-compatible clone chips intermittently return CoreNFC Stack Error (code 104) or No response from tag (code 102) for queryNDEFStatus/readNDEF right after connecting, even though raw sendMiFareCommand reads/writes work fine. On those tags onDiscovered fires only occasionally (or never), making them effectively undetectable through this plugin — while other apps that use a plain NFCNDEFReaderSession / raw session read them instantly.

Fix

Make the NDEF probe best-effort. On a probe error, still deliver the TagPigeon instead of dropping it:

• queryNDEFStatus error → deliver the tag without NDEF info.
• readNDEF error → deliver the tag with the status/capacity already obtained, just without a cached message.

The app keeps the discovery and can communicate with the tag over its raw interface (sendMiFareCommand, etc.). Successful probes are completely unchanged, so NDEF reading behavior for well-behaved tags is identical.

Notes

• Pure iOS-side change, single function (convert(NFCNDEFTag)), no public API change.
• readNDEF already special-cased code 403 ("no NDEF message present") as non-fatal; this generalizes the same "never lose the discovery over a probe error" principle to all probe failures.