refactor: hard-fork GSD -> MSD (Make Software Done)

Mechanical rename produced by scripts/msd-rename.cjs: gsd/Gsd/GSD -> msd/Msd/MSD
across contents and paths, upstream package/repo coordinates -> @golem15/msd-core
and golem15com/msd-core. Deep links into upstream history, sibling upstream
packages, the GSD-2 import feature, CHANGELOG.md and .changeset/ are kept as-is.

Hand edits on top: MSD block-letter banner and logos, LICENSE copyright line,
package/plugin identity, regenerated lockfile, install-tree fixtures, derived
registries and benchmark baseline; migration checksum baseline re-locked
(MSD keeps its own install state, so no install had applied the old sums);
sort-order and regex-escaped expectations in tests adjusted.

tests/capability-matrix-sync.test.cjs

@@ -6,7 +6,7 @@
  * The committed docs/reference/capability-matrix.md FRESHNESS guard
  * (`gen-capability-matrix.cjs --check` + byte-for-byte) moved to
  * `npm run lint:generated-sync`, where it runs against the committed file in
- * both local and CI lint lanes — instead of being masked by gsd-test's
+ * both local and CI lint lanes — instead of being masked by msd-test's
  * `npm run build` leg regenerating artifacts. What remains here are the
  * architectural CONTENT invariants the matrix must satisfy regardless of how
  * freshness is enforced: every first-party capability appears as a row, and
@@ -20,7 +20,7 @@ const path = require('node:path');
 
 const ROOT = path.resolve(__dirname, '..');
 const MATRIX = path.join(ROOT, 'docs', 'reference', 'capability-matrix.md');
-const registry = require('../gsd-core/bin/lib/capability-registry.cjs');
+const registry = require('../msd-core/bin/lib/capability-registry.cjs');
 
 describe('capability-matrix content invariants (ADR-1244 Phase 6)', () => {
   test('every first-party capability in the registry appears as a matrix row', () => {