docs(licence): long-form prose → CC-BY-SA-4.0 (9 docs)

Re-applies the owner-authorised relicensing (orig f6cc023) that never
landed on main: move 9 long-form prose docs from MPL-2.0 to the
estate-designated prose licence CC-BY-SA-4.0 (per GOVERNANCE.adoc:
"MPL-2.0 for code, CC-BY-SA-4.0 for prose"; already used in 29+ files).

Header-line swap only; copyright / SPDX-FileCopyrightText lines untouched.

Files: FOUNDATION_CONTRACT.md, docs/CLAIMS_AUDIT.adoc,
docs/echo-types/{fibration-package,universal-property}.adoc,
docs/theorem-index.md, wiki/{Architecture,Overview,Roadmap,Working-Rules}.adoc.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VwbFNQJw23tW8tqM7utWku

Author: claude

FOUNDATION_CONTRACT.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>
 -->
 

docs/CLAIMS_AUDIT.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>
 = Claims Audit — Gate G1 input
 :toc: macro

docs/echo-types/fibration-package.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>
 // SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 = echo-types: The Fibration Package

docs/echo-types/universal-property.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>
 // SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 = echo-types: The Universal Property Story

docs/theorem-index.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>
 -->
 <!-- SPDX-FileCopyrightText: 2025-2026 Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk> -->

wiki/Architecture.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 <j.d.a.jewell@open.ac.uk>
 = Architecture
 :toc: macro

wiki/Overview.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 <j.d.a.jewell@open.ac.uk>
 = Overview
 :toc: macro

wiki/Roadmap.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 <j.d.a.jewell@open.ac.uk>
 = Roadmap
 :toc: macro

wiki/Working-Rules.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 <j.d.a.jewell@open.ac.uk>
 = Working Rules
 :toc: macro