bump some magic numbers

zephcore/Kconfig

@@ -146,10 +146,11 @@ config ZEPHCORE_MAX_CLIENTS
 
 config ZEPHCORE_MAX_NEIGHBOURS
 	int "Maximum tracked neighbors"
-	default 16
+	default 50
 	help
 	  Maximum number of neighboring repeaters to track.
 	  Set to 0 to disable neighbor tracking.
+	  Default 50 matches upstream Arduino MeshCore repeater variants.
 
 config ZEPHCORE_MAX_REGION_ENTRIES
 	int "Maximum region entries"

zephcore/app/RepeaterMesh.h

@@ -41,7 +41,7 @@
   #ifdef CONFIG_ZEPHCORE_MAX_NEIGHBOURS
     #define MAX_NEIGHBOURS  CONFIG_ZEPHCORE_MAX_NEIGHBOURS
   #else
-    #define MAX_NEIGHBOURS  16
+    #define MAX_NEIGHBOURS  50
   #endif
 #endif
 

zephcore/boards/linux_native/linux_common.conf

@@ -74,6 +74,18 @@ CONFIG_KERNEL_BIN_NAME="zephcore_native_linux"
 # transceive path allocates flat scatter/gather buffers per call.
 CONFIG_HEAP_MEM_POOL_SIZE=131072
 
+# ========== Mesh capacity (companion role) ==========
+# An SBC has orders of magnitude more RAM than an nRF52, so raise the two
+# companion sizing limits well above the MCU defaults. These are static BSS
+# arrays, trivially affordable on a Pi.
+#   Offline queue: QueuedFrame is 173 B each → 2048 ≈ 354 KB. Buffers inbound
+#   messages while the companion app is away (the always-on gateway case).
+#   Contacts: stored locally; note the BLE/USB companion protocol reports the
+#   cap as a single MAX_CONTACTS/2 byte that saturates at 255 (=510), so the
+#   app's displayed limit tops out at 510 even though the node holds more.
+CONFIG_ZEPHCORE_OFFLINE_QUEUE_SIZE=2048
+CONFIG_ZEPHCORE_MAX_CONTACTS=2048
+
 # ========== Disable MCU-specific options that don't apply ==========
 CONFIG_USB_DEVICE_STACK_NEXT=n
 CONFIG_USB_DEVICE_STACK=n