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.

src/uat.cts

@@ -299,7 +299,7 @@ function cmdAuditUat(cwd: string, raw: boolean): void {
     }
 
     // Process deferred-items.md (#2287) — the SCOPE BOUNDARY convention
-    // (agents/gsd-executor.md) has the executor log out-of-scope discoveries
+    // (agents/msd-executor.md) has the executor log out-of-scope discoveries
     // to this file; nothing previously read it back. Surface every
     // UNRESOLVED entry (see parseDeferredItems for the resolved/unresolved
     // parsing rule) as a 'deferred'-typed result, keeping deferred-items.md
@@ -1871,7 +1871,7 @@ function parseGapsTableItems(sectionBody: string): UatItem[] {
 
 /**
  * Extract unresolved entries from a phase directory's `deferred-items.md`
- * (#2287) — the SCOPE BOUNDARY convention `agents/gsd-executor.md` instructs
+ * (#2287) — the SCOPE BOUNDARY convention `agents/msd-executor.md` instructs
  * the executor to follow: "Log out-of-scope discoveries to `deferred-items.md`
  * in the phase directory". Nothing previously read this file back, so a
  * deferred entry was permanently invisible outside the phase directory.