Add ham radio profile with FLEcli package

Introduces a custom packages overlay (pkgs/) for packages not in nixpkgs.
Adds FLEcli v0.1.7 for processing amateur radio logs (SOTA, POTA, WWFF).
Enables ham-radio profile on beefy.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

hosts/beefy/default.nix

@@ -7,6 +7,7 @@
     ../../common/cluster-member.nix  # Consul + storage clients
     ../../common/cluster-tools.nix    # Nomad CLI (no service)
     ../../common/docker.nix           # Docker daemon
+    ../../common/ham-radio.nix        # Ham radio tools (FLEcli)
     ./hardware.nix
   ];