Add licensing information and update README for KIBU

- Introduced additional terms under Section 7 of the GNU AGPL v3 for KIBU, including attribution, marking of modified versions, and trademark usage.
- Added MIT License file for clarity on licensing options.
- Updated README.md to reflect the new licensing terms, including detailed usage rights and obligations.
- Created REUSE.toml for SPDX compliance and license annotations.
- Added THIRD_PARTY_NOTICES.md to clarify third-party dependencies and their licenses.
- Updated various source files and scripts to include SPDX headers for copyright and licensing.
- Enhanced footer in layout to display licensing information and project link.
- Implemented a new license page to present the AGPL and additional terms clearly.

package.json

@@ -2,6 +2,7 @@
   "name": "kibu",
   "version": "0.1.0",
   "private": true,
+  "license": "AGPL-3.0-only AND LicenseRef-KIBU-Additional-Terms",
   "scripts": {
     "dev": "next dev --hostname 127.0.0.1",
     "build": "next build",