Add daily ZFS health check with ntfy alerts and introduce ntfy role

Add a zfs-alerts module that runs a daily health check on ZFS machines,
sending detailed ntfy notifications for degraded pools, data errors, or
drive errors. Introduce an "ntfy" system role to decouple ntfy alerting
from the server/personal roles, and assign it to all machines.

machines/fry/properties.nix

@@ -8,6 +8,7 @@
   systemRoles = [
     "personal"
     "dns-challenge"
+    "ntfy"
   ];
 
   hostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAID/Df5lG07Il7fizEgZR/T9bMlR0joESRJ7cqM9BkOyP";

machines/howl/properties.nix

@@ -7,6 +7,7 @@
 
   systemRoles = [
     "personal"
+    "ntfy"
   ];
 
   hostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIEQi3q8jU6vRruExAL60J7GFO1gS8HsmXVJuKRT4ljrG";

machines/ponyo/properties.nix

@@ -15,6 +15,7 @@
     "dailybot"
     "gitea"
     "librechat"
+    "ntfy"
   ];
 
   hostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMBBlTAIp38RhErU1wNNV5MBeb+WGH0mhF/dxh5RsAXN";

machines/storage/s0/properties.nix

@@ -18,6 +18,7 @@
     "linkwarden"
     "outline"
     "dns-challenge"
+    "ntfy"
   ];
 
   hostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAwiXcUFtAvZCayhu4+AIcF+Ktrdgv9ee/mXSIhJbp4q";

machines/zoidberg/properties.nix

@@ -8,6 +8,7 @@
   systemRoles = [
     "personal"
     "media-center"
+    "ntfy"
   ];
 
   hostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHvdC1EiLqSNVmk5L1p7cWRIrrlelbK+NMj6tEBrwqIq";