Initial commit: ServerManager GUI application

CustomTkinter desktop app for managing remote servers.
Features: SSH terminal, SFTP file transfer, key management,
background status monitoring, server CRUD with dark theme.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

config/servers.example.json

@@ -0,0 +1,17 @@
+{
+  "servers": [
+    {
+      "alias": "my-server",
+      "ip": "1.2.3.4",
+      "port": 22,
+      "user": "root",
+      "password": "YOUR_PASSWORD_HERE",
+      "type": "ssh",
+      "notes": "Example server"
+    }
+  ],
+  "ssh_key": {
+    "type": "ed25519",
+    "path": "~/.ssh/id_ed25519"
+  }
+}