chore(licence): normalise to MPL-2.0 (code) + CC-BY-SA-4.0 (docs) (#40)

- LICENSES/ = {MPL-2.0.txt, CC-BY-SA-4.0.txt}; root LICENSE = verbatim MPL-2.0 (GitHub display)
- SPDX: code -> MPL-2.0, docs (.md/.adoc) -> CC-BY-SA-4.0; metadata/badge fixes; vendored untouched

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.claude/CLAUDE.md

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 # RSR-compliant .gitattributes
 
 * text=auto eol=lf

.gitattributes

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 # Funding platforms for hyperpolymath projects
 # See: https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/displaying-a-sponsor-button-in-your-repository
 

.github/FUNDING.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 # Dependabot configuration for RSR-compliant repositories
 # Covers common ecosystems - remove unused ones for your project
 

.github/dependabot.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 name: BoJ Server Build Trigger
 on:
   push:

.github/workflows/boj-build.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 name: GitHub Pages
 on:
   push:

.github/workflows/casket-pages.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 # Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 #
 # dogfood-gate.yml — Hyperpolymath Dogfooding Quality Gate

.github/workflows/dogfood-gate.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 name: Governance
 
 on:

.github/workflows/governance.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 name: Hypatia Security Scan
 
 on:

.github/workflows/hypatia-scan.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 # Instant Forge Sync - Triggers propagation to all forges on push/release
 name: Instant Sync
 on: