feat: Update application metadata and layout for shiro Assistant

- Changed title and description in layout.tsx to reflect new branding.
- Updated favicon and apple icons for better visual identity.
- Set HTML language attribute to Japanese.

refactor: Clean up console logs and improve error messages

- Removed unnecessary console logs from various files.
- Updated error messages to use "投稿" instead of "質問" for consistency.

feat: Enhance question and answer handling

- Modified question detail page to improve user experience with clearer error messages.
- Updated new question page to provide better guidance for users on what to post.
- Implemented caching for question fetching to improve performance.

fix: Adjust status filtering logic in questions page

- Updated status filter to handle multiple statuses and improve query efficiency.
- Refined search functionality to enhance user experience.

style: Update UI elements for better clarity and consistency

- Changed button labels from "新規質問" to "新規投稿" for clarity.
- Improved breadcrumb navigation and header titles for better user guidance.

chore: Add new SVG icons for branding

- Added favicon.svg and blog-icon.svg for enhanced visual representation.

Author: nomhiro