docs: update license from AGPL to PMPL

- Replace AGPL-3.0-or-later with PMPL-1.0-or-later
- Update license name and URLs
- Align with palimpsest-license standard

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Your Name

README.adoc

@@ -437,9 +437,9 @@ See `.claude/CLAUDE.md` for complete language policy.
 
 == License
 
-SPDX-License-Identifier: `AGPL-3.0-or-later OR MIT`
+SPDX-License-Identifier: `PMPL-1.0-or-later OR MIT`
 
-Dual-licensed under GNU Affero General Public License v3.0 or later, or Palimpsest-MPL-1.0 License. See link:LICENSE.txt[LICENSE.txt] for details.
+Dual-licensed under Palimpsest-MPL License v3.0 or later, or Palimpsest-MPL-1.0 License. See link:LICENSE.txt[LICENSE.txt] for details.
 
 == Citation