Replace Uptime Kuma with Gatus for declarative uptime monitoring

Gatus is configured entirely via YAML (mapped from Nix attrsets),
making nix-config the single source of truth for all monitoring
config instead of Uptime Kuma's web UI/SQLite database.

CLAUDE.md

@@ -67,6 +67,12 @@ IP allocation convention: VMs `.10-.49`, containers `.50-.89`, incus `.90-.129`
 
 `flake.nix` applies patches from `/patches/` to nixpkgs before building (workaround for nix#3920).
 
+### Service Dashboard & Monitoring
+
+When adding or removing a web-facing service, update both:
+- **Gatus** (`common/server/gatus.nix`) — add/remove the endpoint monitor
+- **Dashy** — add/remove the service entry from the dashboard config
+
 ### Key Conventions
 
 - Uses `doas` instead of `sudo` everywhere
@@ -83,3 +89,5 @@ IP allocation convention: VMs `.10-.49`, containers `.50-.89`, incus `.90-.129`
 ## Git Worktree Requirement
 
 When instructed to work in a git worktree (e.g., via `isolation: "worktree"` or told to use a worktree), you **MUST** do so. If you are unable to create or use a git worktree, you **MUST** stop work immediately and report the failure to the user. Do not fall back to working in the main working tree.
+
+When applying work from a git worktree back to the main branch, commit in the worktree first, then use `git cherry-pick` from the main working tree to bring the commit over. Do not use `git checkout` or `git apply` to copy files directly. Do **not** automatically apply worktree work to the main branch — always ask the user for approval first.

common/server/default.nix

@@ -17,6 +17,6 @@
     ./actualbudget.nix
     ./unifi.nix
     ./ntfy.nix
-    ./uptime-kuma.nix
+    ./gatus.nix
   ];
 }

common/server/gatus.nix

@@ -0,0 +1,146 @@
+{ lib, config, ... }:
+
+let
+  cfg = config.services.gatus;
+  port = 31103;
+in
+{
+  options.services.gatus = {
+    hostname = lib.mkOption {
+      type = lib.types.str;
+      example = "status.example.com";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.gatus = {
+      environmentFile = "/run/agenix/ntfy-token";
+      settings = {
+        storage = {
+          type = "sqlite";
+          path = "/var/lib/gatus/data.db";
+        };
+
+        web = {
+          address = "127.0.0.1";
+          port = port;
+        };
+
+        alerting.ntfy = {
+          url = "https://ntfy.neet.dev";
+          topic = "service-failures";
+          priority = 4;
+          default-alert = {
+            enabled = true;
+            failure-threshold = 3;
+            success-threshold = 2;
+            send-on-resolved = true;
+          };
+          token = "$NTFY_TOKEN";
+        };
+
+        endpoints = [
+          {
+            name = "Gitea";
+            group = "services";
+            url = "https://git.neet.dev";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "The Lounge";
+            group = "services";
+            url = "https://irc.neet.dev";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "ntfy";
+            group = "services";
+            url = "https://ntfy.neet.dev/v1/health";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Librechat";
+            group = "services";
+            url = "https://chat.neet.dev";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Owncast";
+            group = "services";
+            url = "https://live.neet.dev";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Nextcloud";
+            group = "services";
+            url = "https://neet.cloud";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == any(200, 302)"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Element Web";
+            group = "services";
+            url = "https://chat.neet.space";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Mumble";
+            group = "services";
+            url = "tcp://voice.neet.space:23563";
+            interval = "5m";
+            conditions = [
+              "[CONNECTED] == true"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+          {
+            name = "Navidrome";
+            group = "services";
+            url = "https://navidrome.neet.cloud";
+            interval = "5m";
+            conditions = [
+              "[STATUS] == 200"
+            ];
+            alerts = [{ type = "ntfy"; }];
+          }
+        ];
+      };
+    };
+    services.nginx.enable = true;
+    services.nginx.virtualHosts.${cfg.hostname} = {
+      enableACME = true;
+      forceSSL = true;
+      locations."/" = {
+        proxyPass = "http://127.0.0.1:${toString port}";
+        proxyWebsockets = true;
+      };
+    };
+  };
+}

common/server/uptime-kuma.nix

@@ -1,36 +0,0 @@
-{ lib, config, ... }:
-
-let
-  cfg = config.services.uptime-kuma;
-  port = 3001;
-in
-{
-  options.services.uptime-kuma = {
-    hostname = lib.mkOption {
-      type = lib.types.str;
-      example = "status.example.com";
-    };
-  };
-
-  config = lib.mkIf cfg.enable {
-    services.uptime-kuma.settings = {
-      HOST = "127.0.0.1";
-      PORT = toString port;
-    };
-
-    # backups
-    backup.group."uptime-kuma".paths = [
-      "/var/lib/uptime-kuma"
-    ];
-
-    services.nginx.enable = true;
-    services.nginx.virtualHosts.${cfg.hostname} = {
-      enableACME = true;
-      forceSSL = true;
-      locations."/" = {
-        proxyPass = "http://127.0.0.1:${toString port}";
-        proxyWebsockets = true;
-      };
-    };
-  };
-}

machines/ponyo/default.nix

@@ -114,6 +114,6 @@
   services.ntfy-sh.hostname = "ntfy.neet.dev";
 
   # uptime monitoring
-  services.uptime-kuma.enable = true;
+  services.gatus.enable = true;
-  services.uptime-kuma.hostname = "status.neet.dev";
+  services.gatus.hostname = "status.neet.dev";
 }