cli: handle SIGPIPE to prevent broken pipe panic

[martinsander00]

Resolves: #3387

Summary

• Rust ignores SIGPIPE at startup, causing println! to panic with "Broken pipe" when piping CLI output to head, grep, etc.
• Reset SIGPIPE to SIG_DFL at the start of main() in all 3 CLI binaries (doublezero, doublezero-geolocation, doublezero-admin) so the process exits silently like standard CLI tools

Lines of Code

Section	Added	Removed
client/doublezero	+5	-0
client/doublezero-geolocation-cli	+5	-0
controlplane/doublezero-admin	+5	-0
Cargo.lock	+3	-0

Testing Verification

• Companion fix for doublezero-solana in cli: fix broken pipe panic when piping output to head/grep doublezerofoundation/doublezero-offchain#317

ubuntu@chi-dn-bm2:~$ doublezero device list | head -n 5
 account                                      | code                  | contributor | location | exchange | device_type | public_ip  | dz_prefixes    | users | max_users | status              | health          | mgmt_vrf   | owner                                        
 8PQkip3CxWhQTdP7doCyhT2kwjSL2csRTdnRg2zbDPs1 | chi-dn-dzd1           | co01        | chi      | xchi     | hybrid      | 100.0.0.1  | 198.18.0.0/24  | 0     | 128       | activated           | ready-for-users | management | DZfHfcCXTLwgZeCRKQ1FL1UuwAwFAZM93g86NMYpfYan 
 4CkvmyquGN4qtXLNj3hpJcqYbb7PCanLbU1rQHHdp6xp | chi-dn-dzd3-delete-me | co01        | chi      | xchi     | hybrid      | 0.1.2.3    | 198.18.4.0/24  | 0     | 0         | activated           | ready-for-users |            | DZfHfcCXTLwgZeCRKQ1FL1UuwAwFAZM93g86NMYpfYan 
 HzndSULmxcc95Zj8c3u3dKKt6YQN7fc1XW92cZvwyxC5 | greg-test-dev         | co01        | chi      | xchi     | hybrid      | 1.2.3.4    | 198.18.42.0/24 | 0     | 0         | activated           | ready-for-users | default    | DZfHfcCXTLwgZeCRKQ1FL1UuwAwFAZM93g86NMYpfYan 
 GV98Pn3xZR3dyMsbD7VMRSrpoN3qj3ch9f69mmW6LHj3 | nikw-test             | co01        | chi      | xchi     | hybrid      | 1.2.3.8    | 198.18.9.0/24  | 0     | 0         | device-provisioning | ready-for-users | default    | DZfHfcCXTLwgZeCRKQ1FL1UuwAwFAZM93g86NMYpfYan 
ubuntu@chi-dn-bm2:~$