chore(licence): normalise to MPL-2.0 + CC-BY-SA-4.0 (canonical pair) (#277)

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

.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/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 (echo-types)
 :toc: preamble

.machine_readable/bot_directives/README.adoc

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MPL-2.0
+// SPDX-License-Identifier: CC-BY-SA-4.0
 // SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell
 = Bot directives — echo-types
 :toc:

.machine_readable/integrations/README.adoc

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MPL-2.0
+// SPDX-License-Identifier: CC-BY-SA-4.0
 = Integrations (echo-types)
 :toc:
 

.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 — echo-types
 :toc: left

.machine_readable/svc/k9/README.adoc

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MPL-2.0
+// SPDX-License-Identifier: CC-BY-SA-4.0
 = K9 Contractiles (echo-types)
 :toc: left
 :icons: font

CITATION.cff

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: CC-BY-4.0
+# SPDX-License-Identifier: MPL-2.0
 # SPDX-FileCopyrightText: 2025-2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 cff-version: 1.2.0
 title: "echo-types: a definitionally-grounded, loss-graded reindexing modality (Agda)"

CLAUDE.md

@@ -442,7 +442,7 @@ form — nothing is re-proved.
 (draft PR), plus an oikos doc commit (draft PR):
 
 * **Commit A — `docs(licence): long-form prose → CC-BY-SA-4.0 (9 docs)`**
-  (`879ec9b`). Header-line swap only (`SPDX-License-Identifier: MPL-2.0` →
+  (`879ec9b`). Header-line swap only (`SPDX-License-Identifier: CC-BY-SA-4.0` →
   `…: CC-BY-SA-4.0`) on `FOUNDATION_CONTRACT.md`, `docs/theorem-index.md`,
   `docs/CLAIMS_AUDIT.adoc`, `docs/echo-types/{fibration-package,universal-property}.adoc`,
   `wiki/{Architecture,Overview,Roadmap,Working-Rules}.adoc`. Copyright /

FOUNDATIONS_BRIDGE.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0 AND CC-BY-SA-4.0
+SPDX-License-Identifier: CC-BY-SA-4.0 AND CC-BY-SA-4.0
 SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 Licence is owner-directed: MPL-2.0 (code) and CC-BY-SA-4.0 (documentation),
 applied across echo-types, tropical-resource-typing, and any my-lang consumer.

Fidelity-OPEN-postulates.md

@@ -1,5 +1,5 @@
 <!--
-SPDX-License-Identifier: MPL-2.0
+SPDX-License-Identifier: CC-BY-SA-4.0
 SPDX-FileCopyrightText: 2025-2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 -->