Migrate from Kirby CMS to Hugo with Gokarna theme

- Remove all Kirby/PHP files
- Add Hugo config with Gokarna theme as git submodule
- Add nginx + Hugo Dockerfile replacing PHP/Apache
- Update deploy.php to run hugo after git pull
- Update .gitignore for Hugo output

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

hugo.toml

@@ -0,0 +1,20 @@
+baseURL = "https://robbis.space"
+defaultContentLanguage = "en"
+languageCode = "en"
+theme = "gokarna"
+title = "robbis.space"
+
+[params]
+description = ""
+footer = "Robbi"
+
+[menu]
+[[menu.main]]
+name = "Home"
+url = "/"
+weight = 1
+
+[[menu.main]]
+name = "Posts"
+url = "/posts/"
+weight = 2