v1.0.0: Boundary mode with bidirectional LoRa↔TCP transport

Vendor microReticulum library with boundary mode transport fixes:
- Two-whitelist system gates backbone traffic (local addresses +
  mentioned addresses from local devices)
- Allow control_hashes and local destinations through boundary filter
  (fixes backbone→LoRa path discovery)
- Fix get_cached_packet() to call unpack() instead of update_hash()
  (fixes empty destination_hash in path responses)
- LRPROOF Identity::recall null guard
- remaining_hops HEADER_1/BROADCAST fix for final-hop delivery
- PROOF packets excluded from boundary wrapping
- Iterator invalidation fix in transport table cleanup
- is_backbone flag replaces string matching for interface identification

Firmware changes:
- Set is_backbone(true) on backbone TCP interface
- Rename default TcpInterface name to BackboneInterface
- Update comments for dual-use TcpInterface (backbone + local AP)
- Use vendored lib/microReticulum instead of PlatformIO registry

BoundaryMode.h

@@ -20,7 +20,7 @@
 // The boundary node operates with TWO RNS interfaces:
 //
 //   1. LoRaInterface (MODE_GATEWAY) — radio side, handles LoRa mesh
-//   2. TcpInterface  (MODE_BOUNDARY) — WiFi side, connects to TCP backbone
+//   2. BackboneInterface (MODE_BOUNDARY) — WiFi side, connects to TCP backbone
 //
 // RNS Transport is ALWAYS enabled in boundary mode.
 // Packets received on either interface are routed through Transport