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

.github/workflows/governance.yml

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

.github/workflows/hypatia-scan.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/scorecard.yml

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

.machine_readable/6a2/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>
 # A2ML 6a2 Directory
 

.machine_readable/self-validating/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>
 = K9 Contractiles
 :toc: left

.machine_readable/svc/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>
 = `.machine_readable/svc/` — Service components for error-lang
 :toc:

ABI-FFI-README.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>
 -->
 {{~ Aditionally delete this line and fill out the template below ~}}

CHANGELOG.md

@@ -1,6 +1,6 @@
 <!--
 <!-- Owner: Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk> -->
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath)
 -->
 

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

CONTINUATION-GUIDE.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>
 = Error-Lang: Continuation Guide
 :toc: