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/lint-default-flip-documentation.cjs

@@ -16,7 +16,7 @@
  *
  * The DEFECT text names two surfaces: `CONFIG_DEFAULTS` and
  * `buildNewProjectConfig`. This check covers ONLY the single-source-of-truth
- * defaults manifest, `gsd-core/bin/shared/config-defaults.manifest.json`
+ * defaults manifest, `msd-core/bin/shared/config-defaults.manifest.json`
  * (what `CONFIG_DEFAULTS` in `src/configuration.cts` / `src/config.cts`
  * actually loads at runtime) — because it is pure JSON, a resolved
  * key→value-map diff between base and head is trivially reliable: no line
@@ -53,7 +53,7 @@ const cp = require('node:child_process');
 const { ExitError, runMain } = require('./lib/cli-exit.cjs');
 
 const ROOT = path.join(__dirname, '..');
-const MANIFEST_PATH = path.join('gsd-core', 'bin', 'shared', 'config-defaults.manifest.json');
+const MANIFEST_PATH = path.join('msd-core', 'bin', 'shared', 'config-defaults.manifest.json');
 const BREAKING_CHANGES_RE = /^#{1,6}\s*Breaking Changes\b/im;
 
 /**
@@ -170,7 +170,7 @@ function main() {
         + 'config-defaults.manifest.json (DEFECT.DEFAULT-FLIP-DOCUMENTATION) but the PR body has no\n'
         + '`## Breaking Changes` section. Add one covering: (a) when the new default takes effect\n'
         + '(config-set, fresh project, regenerated config), (b) the opt-back-in command\n'
-        + '(`gsd config-set <key> <old-value>`), (c) effect on in-flight artifacts. Changed default(s):\n'
+        + '(`msd config-set <key> <old-value>`), (c) effect on in-flight artifacts. Changed default(s):\n'
         + detail,
     );
   }