refactor(security): migrate hardcoded credentials and SSH keys to sops-nix

modules/common/default.nix

@@ -1,4 +1,8 @@
 {
+  imports = [
+    ./secrets.nix
+  ];
+
   config = {
     homelab = {
       services.openssh.enable = true;
@@ -12,5 +16,10 @@
 
     # Set your time zone.
     time.timeZone = "Europe/Brussels";
+
+    sops = {
+      defaultSopsFile = ../../secrets/secrets.yaml;
+      age.keyFile = "/var/lib/sops-nix/key.txt";
+    };
   };
 }

modules/common/secrets.nix

@@ -0,0 +1,18 @@
+{ config, lib, ... }:
+
+{
+  sops.secrets = {
+    # -- User Public Keys (Anti-Fingerprinting) --
+    "user_keys_admin" = { neededForUsers = true; };
+    "user_keys_deploy" = { neededForUsers = true; };
+    "user_keys_backup" = { neededForUsers = true; };
+
+    # -- Infrastructure Metadata --
+    # Hugo TODO: Populate these in your .sops.yaml / secrets file
+    "acme_email" = {};
+    "cloudflare_dns_token" = {};
+    "pgadmin_email" = {};
+    "gitea_mailer_from" = {};
+    "vaultwarden_smtp_from" = {};
+  };
+}