Merge origin/main into fix/glama-license-tables-proof (resolve conflicts)

- README.md: kept the pre-existing MPL-2.0 header + the branch title; dropped
  main's standardization-sweep duplicate (a second // CC-BY-SA-4.0 header that
  collided with the file's existing MPL-2.0 header and the PR's MPL-2.0 intent).
- site/index.md: honoured main's deletion (#233 replaced it with the new
  site/index.html website). Branch's only change there was a cartridge-count
  bump, carried as a flag (see PR comment) rather than into the deleted file.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: hyperpolymath

.claude/CLAUDE.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->
 # CLAUDE.md - AI Assistant Instructions

.claude/PROJECT.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->
 # BOJ Server - Claude Code Instructions

.devcontainer/README.adoc

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MPL-2.0
+// SPDX-License-Identifier: CC-BY-SA-4.0
 // Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 = Dev Container Usage
 :author: Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>

.github/CICD-CHANGES-2026-06-04.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->
 

.github/CODE_OF_CONDUCT.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->
 # Code of Conduct

.github/CONTRIBUTING.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->
 # Contributing to boj-server