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>

.gitignore

@@ -0,0 +1,16 @@
+# Credentials - NEVER commit
+config/servers.json
+
+# Python
+__pycache__/
+*.pyc
+*.pyo
+*.egg-info/
+dist/
+build/
+*.spec
+
+# IDE
+.vscode/
+.idea/
+*.swp