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.

LICENSES/MIT.txt

@@ -0,0 +1,18 @@
+MIT License
+
+Copyright (c) 2026 Paul Schoeneck
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the
+following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial
+portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
+EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+USE OR OTHER DEALINGS IN THE SOFTWARE.