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

hosts/jpporta-nixos/home.nix

@@ -1,3 +1,6 @@
+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.
+Warning: Identity file /home/jpporta/.ssh/id_rsa not accessible: No such file or directory.
 {
   config,
   pkgs,
@@ -32,6 +35,7 @@
     ../../modules/home-manager/tmux
     ../../modules/home-manager/openspec
     ../../modules/home-manager/power-profiles
+    ../../modules/home-manager/ntfy-notify
 
     inputs.zen-browser.homeModules.beta
   ];
@@ -91,8 +95,9 @@
     };
     openspec.enable = true;
     power-profiles.enable = true;
-  };
+    ntfy-notify.enable = true;
 
+  };
   home.packages =
     let
       mediaplayerPython = pkgs.python3.withPackages (ps: with ps; [ pygobject3 ]);