migrate git URLs from git.t-juice.club to code.t-juice.club

Update all flake URLs to use the new Forgejo instance. This includes
auto-upgrade, nixos-rebuild-test, homelab-deploy listener, nixos-exporter,
nix-cache02 builder, and the bootstrap script.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -326,7 +326,7 @@ Use `nix flake show` or `nix develop -c ansible-inventory --graph` to list all h
 - `nixpkgs-unstable` - Unstable channel (available via overlay as `pkgs.unstable.<package>`)
 - `nixos-exporter` - NixOS module for exposing flake revision metrics (used to verify deployments)
 - `homelab-deploy` - NATS-based remote deployment tool for test-tier hosts
-- Custom packages from git.t-juice.club:
+- Custom packages from code.t-juice.club:
   - `alerttonotify` - Alert routing
 
 ### Network Architecture
@@ -355,7 +355,7 @@ Most hosts use OpenBao (Vault) for secrets:
 
 All hosts pull updates daily from:
 ```
-git+https://git.t-juice.club/torjus/nixos-servers.git
+git+https://code.t-juice.club/torjus/nixos-servers.git
 ```
 
 Configured in `/system/autoupgrade.nix`: