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

@@ -168,7 +168,7 @@ See link:ROADMAP.adoc[ROADMAP.adoc] for the development plan.
 Dual-licensed under:
 
 * Palimpsest-MPL-1.0 License
-* AGPL-3.0-or-later
+* PMPL-1.0-or-later
 
 With additional philosophical overlay: LicenseRef-Palimpsest-0.5