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/shell-command-projection-md-normalize.test.cjs

@@ -32,7 +32,7 @@ const fc = require('fast-check');
 const fs = require('fs');
 const os = require('node:os');
 const path = require('path');
-const { normalizeContent, platformWriteSync } = require('../gsd-core/bin/lib/shell-command-projection.cjs');
+const { normalizeContent, platformWriteSync } = require('../msd-core/bin/lib/shell-command-projection.cjs');
 const { cleanup } = require('./helpers.cjs');
 
 const MD = 'roadmap.md';
@@ -105,7 +105,7 @@ describe('#3854: write normalization preserves tight multi-line lists', () => {
   });
 
   test('the write seam (platformWriteSync) lands the same bytes — end-to-end guard', () => {
-    const osTmp = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-3854-'));
+    const osTmp = fs.mkdtempSync(path.join(os.tmpdir(), 'msd-3854-'));
     try {
       const target = path.join(osTmp, 'ROADMAP.md');
       const tight = '# Roadmap v1.0\n\n- item one wraps\n  continuation one\n- item two wraps\n  continuation two\n';