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/qa/paths.cjs

@@ -83,7 +83,7 @@ function realpathNearestAncestor(candidate, realpathFn = defaultRealpath) {
  * MACOS SYMLINK CASE (do not "simplify" this back to a lexical compare): on macOS,
  * `os.tmpdir()` / `TMPDIR` resolves to `/var/folders/...`, which is itself a symlink to
  * `/private/var/folders/...`. `fs.mkdtempSync` returns the unresolved `/var/...` form, but
- * `gsd-tools` output paths are realpath-resolved by the OS/child process to the
+ * `msd-tools` output paths are realpath-resolved by the OS/child process to the
  * `/private/var/...` form. Comparing those two strings *lexically* makes the very same
  * directory compare as "outside the project" and fires a spurious `value-hygiene` smell on
  * every macOS run — and would make a legitimate `resolveWithin` call throw a false containment