chore: GitHub Actions 워크플로우 개선 및 코드 스타일 가이드 추가 (#22)

* chore: improve GitHub Actions workflows

- Update code-quality workflow to trigger on all branches except main
- Add --ignore-unknown flag to Prettier check
- Improve PR auto-labeler with action-remove-labels for better reliability
- Update production-deploy workflow to use docker image prune instead of system prune
- Preserve SSL certificate volumes during deployment cleanup
- Enhance Discord notification with commit links

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

* style: apply prettier formatting to components

- Format inputField components with double quotes and sorted imports
- Format stepIndicator component with sorted Tailwind classes
- Format tag component with consistent quote style
- Apply automatic Tailwind class sorting

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

* chore: add Gemini Code Assistant configuration

- Add comprehensive code style guide with naming conventions
- Define component rules and TypeScript patterns
- Document Tailwind CSS v4 usage with ygi prefix
- Include folder structure guidelines
- Add commit convention and best practices
- Configure review style for code reviews

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

* style: apply tabs indentation to CSS and app files

- Convert spaces to tabs in all CSS files following prettier config
- Apply consistent indentation to app/layout.tsx and app/globals.css
- Ensure all files follow useTabs: true configuration

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: RookieAND

.gemini/config.yml

@@ -0,0 +1,14 @@
+have_fun: false
+code_review:
+    disable: false
+    comment_severity_threshold: MEDIUM
+    max_review_comments: -1
+    pull_request_opened:
+        help: false
+        summary: true
+        code_review: true
+ignore_patterns:
+    - ".github/"
+    - ".claude/"
+    - ".cursor/"
+    - ".vscode/"