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/write-set.test.cjs

@@ -3,7 +3,7 @@
 /**
  * Behavioral tests for write-set.cjs
  *
- * Module: gsd-core/bin/lib/write-set.cjs
+ * Module: msd-core/bin/lib/write-set.cjs
  * Exports: writeSetComplete (Result<T> is a pure type re-exported at compile
  * time only — nothing to assert on it at runtime beyond markdown-table.cjs's
  * own re-export continuing to work, covered by tests/markdown-table.test.cjs).
@@ -19,7 +19,7 @@ const { test, describe } = require('node:test');
 const assert = require('node:assert/strict');
 const fc = require('./helpers/fast-check-setup.cjs');
 
-const { writeSetComplete } = require('../gsd-core/bin/lib/write-set.cjs');
+const { writeSetComplete } = require('../msd-core/bin/lib/write-set.cjs');
 
 describe('writeSetComplete', () => {
   test('every surface applied → true', () => {