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.

scripts/check-glossary-refs.cjs

@@ -37,7 +37,7 @@ const fs = require('node:fs');
 const path = require('node:path');
 
 const { ExitError, runMain } = require('./lib/cli-exit.cjs');
-const { tryWithinRoot, PathAcceptance } = require('../gsd-core/bin/lib/security.cjs');
+const { tryWithinRoot, PathAcceptance } = require('../msd-core/bin/lib/security.cjs');
 
 const ROOT = path.resolve(__dirname, '..');
 const CONTEXT_PATH = path.join(ROOT, 'CONTEXT.md');
@@ -45,7 +45,7 @@ const INSTALL_JS_PATH = path.join(ROOT, 'bin', 'install.js');
 
 /**
  * Directory prefixes this gate can verify against the shipped tree. A token
- * outside these — most importantly `gsd-core/bin/lib/**`, which is generated
+ * outside these — most importantly `msd-core/bin/lib/**`, which is generated
  * and gitignored — is not a claim this gate can check, so it is skipped
  * rather than asserted.
  */
@@ -54,10 +54,10 @@ const TRACKED_PREFIXES = [
   'tests/',
   'scripts/',
   'docs/',
-  'gsd-core/references/',
-  'gsd-core/workflows/',
-  'gsd-core/templates/',
-  'gsd-core/contexts/',
+  'msd-core/references/',
+  'msd-core/workflows/',
+  'msd-core/templates/',
+  'msd-core/contexts/',
   '.github/',
   'eslint-rules/',
 ];