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.

hooks/lib/git-probe.js

@@ -3,8 +3,8 @@
 // distinguishing a GENUINE negative answer (git ran and said "no") from
 // "could not determine" (timeout / spawn failure / signal kill) — #3911.
 //
-// Proven defect: hooks/gsd-worktree-path-guard.js, hooks/gsd-workflow-guard.js,
-// and hooks/gsd-windsurf-pre-write.js each treat spawnSync(git, ..., {timeout})
+// Proven defect: hooks/msd-worktree-path-guard.js, hooks/msd-workflow-guard.js,
+// and hooks/msd-windsurf-pre-write.js each treat spawnSync(git, ..., {timeout})
 // returning a non-zero/empty result as "not applicable" and allow silently.
 // A macOS CI run showed three deny cases land at 2084ms/2112ms/2177ms — just
 // past the 2000ms budget — each returning exit 0 with EMPTY stdout AND EMPTY
@@ -62,7 +62,7 @@ function classifyGitProbe(result) {
  * any exit code, never throws. A no-op when the probe genuinely ran and
  * answered (status 0 or non-zero with no error/signal).
  *
- * @param {string} hookName - e.g. 'gsd-worktree-path-guard'
+ * @param {string} hookName - e.g. 'msd-worktree-path-guard'
  * @param {string} probeLabel - e.g. "git rev-parse --show-toplevel"
  * @param {*} result - the raw spawnSync() return value
  */