chore(licence): normalise to MPL-2.0 + CC-BY-SA-4.0 (canonical pair) (#66)

Estate licence normalisation. LICENSES/={MPL-2.0,CC-BY-SA-4.0}; root
LICENSE=verbatim MPL-2.0 (GitHub display); code->MPL-2.0,
docs(.md/.adoc)->CC-BY-SA-4.0; vendored untouched. Residual mentions
(mostly legitimate anti-AGPL rules): 25. Manual-review licence PR.

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

Author: hyperpolymath

.github/dependabot.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: MPL-2.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 version: 2
 updates:
   - package-ecosystem: "github-actions"

.github/workflows/ci.yml

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

.github/workflows/codeql.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: MPL-2.0
 name: CodeQL Security Analysis
 
 on:

.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/instant-sync.yml

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

.github/workflows/mirror.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: MPL-2.0-or-later
+# SPDX-License-Identifier: MPL-2.0
 name: Mirror to Git Forges
 
 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:

.github/workflows/secret-scanner.yml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: MPL-2.0
 name: Secret Scanner
 
 on:

.machine_readable/agent_instructions/README.adoc

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MPL-2.0
+// SPDX-License-Identifier: CC-BY-SA-4.0
 // Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 = Agent Instructions
 :toc: preamble