Announces now carry an optional capabilities TLV (0x05): a little-endian
bitfield with named bits for upcoming features (prekeys, wifiBulk,
gateway, groups, board, vouch, meshDiagnostics). Old clients skip the
unknown TLV; peers without it decode as nil so features can distinguish
"legacy peer" from "advertises nothing".
PeerCapabilities lives in BitFoundation with a minimal-length encoding
that preserves unknown bits for forward compatibility. Peer capabilities
are stored in the BLE peer registry on verified announce and exposed via
BLEService.peerCapabilities(_:). The local advertisement set is empty
until each feature ships its bit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* Expand protocol coverage with edge-case tests
* Stabilize read receipt transport test
* Stabilize BLE duplicate packet test
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Co-authored-by: jack <jackjackbits@users.noreply.github.com>
