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/docs-guard-registry.cjs

@@ -306,7 +306,7 @@ const DOCS_GUARD_TESTS = {
     'docs/ko-KR/reference/state-md.md',
     'docs/pt-BR/reference/state-md.md',
   ],
-  'tests/gsd-write-guard.test.cjs': ['docs/USER-GUIDE.md'],
+  'tests/msd-write-guard.test.cjs': ['docs/USER-GUIDE.md'],
   'tests/host-integration-descriptors.test.cjs': [
     'docs/reference/host-integration-capability-matrix.md',
   ],
@@ -316,7 +316,7 @@ const DOCS_GUARD_TESTS = {
   'tests/intel.test.cjs': ['*'],
   'tests/inventory-headings-countfree.test.cjs': ['docs/INVENTORY.md'],
   'tests/inventory-manifest-sync.test.cjs': ['docs/INVENTORY.md', 'docs/INVENTORY-MANIFEST.json'],
-  'tests/kilo-upgrades.test.cjs': ['docs/how-to/connect-gsd-mcp-server.md'],
+  'tests/kilo-upgrades.test.cjs': ['docs/how-to/connect-msd-mcp-server.md'],
   'tests/live-config-guard.test.cjs': ['docs/TESTING-SUITES.md'],
   // #3726: pins the `milestone complete` synopsis (English + four localized
   // mirrors), the `--confirm` flag row and the guard-override instructions —