feat: add ntfy-notify home-manager module for desktop kanban notifications (#1)

Adds a new home-manager module `ntfy-notify` that delivers kanban state changes as Linux desktop notifications via **ntfy.sh** + `notify-send` → SwayNC.

**What it does:**
- Installs `ntfy` package
- Creates `~/.config/ntfy/client.yml` with subscription to the `joao-kanban` topic
- Sets up `ntfy-notify.service` (systemd --user) as a persistent subscriber
- Each incoming message fires `notify-send -u critical` → picked up by SwayNC
- Configurable: `server` URL, `subscriptions` list, per-topic priority

**Usage:**
After deploy, start the service once:
```bash
systemctl --user daemon-reload
systemctl --user start ntfy-notify
```

**Companion:** A cron job on the VPS will be needed to push kanban events to the ntfy topic (separate task).

Closes kanban task t_322419fa on ndots board.

---------

Co-authored-by: hermes-bot <hermes@srv1239749>
Reviewed-on: #1

modules/home-manager/ntfy-notify/default.nix

@@ -1,5 +1,3 @@
-Warning: Identity file /home/jpporta/.ssh/id_rsa not accessible: No such file or directory.
-Warning: Identity file /home/jpporta/.ssh/id_rsa not accessible: No such file or directory.
 {
   config,
   lib,
@@ -56,7 +54,7 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    home.packages = [ pkgs.ntfy-sh ];
+    home.packages = [ pkgs.ntfy ];
 
     # Client config with subscription → notify-send mappings.
     # ntfy subscribe (without args) reads subscriptions from here.
@@ -81,7 +79,7 @@ in
       Service = {
         Type = "simple";
         ExecStart = ''
-          ${pkgs.ntfy-sh}/bin/ntfy subscribe
+          ${pkgs.ntfy}/bin/ntfy subscribe
         '';
         Restart = "on-failure";
         RestartSec = 10;