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/helpers/cli-negative.cjs

@@ -1,7 +1,7 @@
 /**
  * CLI negative-matrix harness (#3593).
  *
- * Wraps spawnSync of gsd-core/bin/gsd-tools.cjs so test files can
+ * Wraps spawnSync of msd-core/bin/msd-tools.cjs so test files can
  * assert on structured outputs (exit code, typed reason, stack-trace
  * absence) without each test re-implementing the JSON-errors parsing
  * dance. Hostile values are passed as argv elements — never composed
@@ -29,12 +29,12 @@
 const path = require('node:path');
 const { spawnSync } = require('node:child_process');
 
-const TOOLS_PATH = path.resolve(__dirname, '..', '..', 'gsd-core', 'bin', 'gsd-tools.cjs');
+const TOOLS_PATH = path.resolve(__dirname, '..', '..', 'msd-core', 'bin', 'msd-tools.cjs');
 
 /**
- * Run gsd-tools with the given argv against a project directory.
+ * Run msd-tools with the given argv against a project directory.
  *
- * @param {string[]} argv - argument vector passed to gsd-tools.cjs. Each
+ * @param {string[]} argv - argument vector passed to msd-tools.cjs. Each
  *   element reaches the child as a single argv element regardless of
  *   shell metacharacters in its value.
  * @param {object} options