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-phase-id-drift.cjs

@@ -32,7 +32,7 @@
  *   `hasNameableContent(`.
  *
  * - shell phase-number-arithmetic ban: `$((10#...))` base-10-forced arithmetic
- *   inside `gsd-core/workflows/**\/*.md` and `gsd-core/references/**\/*.md` breaks
+ *   inside `msd-core/workflows/**\/*.md` and `msd-core/references/**\/*.md` breaks
  *   on decimal or multi-segment phase ids and is banned outright. This scan runs
  *   over markdown, not `.cts` source, so its sanction is an HTML comment on the
  *   nearest preceding non-blank line: `<!-- phase-id-owner: <reason> -->`.
@@ -40,7 +40,7 @@
  * - branch-slug fallback drift: a `.replace('{slug}', ... || 'phase')` call
  *   silently substitutes the literal string `'phase'` when a phase's slug
  *   can't be derived, producing a non-identifying branch name like
- *   `gsd/phase-08-phase` (#4126, now fixed via the shared renderPhaseBranchName
+ *   `msd/phase-08-phase` (#4126, now fixed via the shared renderPhaseBranchName
  *   owner in phase-id.cts, consumed by both prior call sites). Sanctioned
  *   the same way as the token/bracket/name-validity rules (`// phase-id-owner:`
  *   on the nearest preceding non-blank line), with a line-level escape for a
@@ -198,7 +198,7 @@ function findNameValidityDrift(text) {
 // #4634: the branch-slug fallback anti-pattern (#4126) — a
 // `.replace('{slug}', ... || 'phase')` call silently falls back to the
 // literal string `'phase'` when a phase's slug can't be derived, producing a
-// non-identifying branch name like `gsd/phase-08-phase`. Now fixed at both
+// non-identifying branch name like `msd/phase-08-phase`. Now fixed at both
 // prior call sites (commands.cts, init.cts) via the shared
 // `renderPhaseBranchName` owner in phase-id.cts; this rule is the ratchet
 // against a THIRD site reintroducing the inline fallback. Deliberately
@@ -295,16 +295,16 @@ function findShellPhaseArithDrift(text) {
 }
 
 // #4634: the markdown scan roots — shell embedded in workflow/reference docs.
-const MD_SCAN_DIRS = [path.join('gsd-core', 'workflows'), path.join('gsd-core', 'references')];
+const MD_SCAN_DIRS = [path.join('msd-core', 'workflows'), path.join('msd-core', 'references')];
 
 // #4568 (epic #4634): the single-segment phase regex ban scans a THIRD root,
 // `agents/**/*.md`, that the #4619 shell-arithmetic extension above never
-// touched — the gsd-code-fixer agent prompts re-derive the phase-number
+// touched — the msd-code-fixer agent prompts re-derive the phase-number
 // grammar too. Reuses the same `walkMd` walker as the shell-arith scan.
 const SINGLE_SEGMENT_SCAN_DIRS = [...MD_SCAN_DIRS, 'agents'];
 
 /**
- * Scan `gsd-core/workflows/**\/*.md` and `gsd-core/references/**\/*.md` for
+ * Scan `msd-core/workflows/**\/*.md` and `msd-core/references/**\/*.md` for
  * unsanctioned `$((10#...))` shell arithmetic. Returns [{ file, line, found }]
  * with repo-relative paths.
  */
@@ -369,7 +369,7 @@ function findSingleSegmentPhaseRegexDrift(text) {
 }
 
 /**
- * Scan `gsd-core/workflows/**\/*.md`, `gsd-core/references/**\/*.md`, and
+ * Scan `msd-core/workflows/**\/*.md`, `msd-core/references/**\/*.md`, and
  * `agents/**\/*.md` for unsanctioned single-optional-dotted-segment phase
  * regexes. Returns [{ file, line, found }] with repo-relative paths.
  */
@@ -561,7 +561,7 @@ function findShellPhasePrintfPadDrift(text) {
 }
 
 /**
- * Scan the shell roots (`gsd-core/workflows/**\/*.md`, `gsd-core/references/**\/*.md`)
+ * Scan the shell roots (`msd-core/workflows/**\/*.md`, `msd-core/references/**\/*.md`)
  * for the two shell-idiom rules (a, c) and the three regex roots (those plus
  * `agents/**\/*.md`) for the extraction-shape rule (b). Returns
  * [{ file, kind, line, found }] with repo-relative paths.
@@ -764,11 +764,11 @@ function main() {
   process.stderr.write('the name-validity predicate — or sanction the site with a dedicated\n');
   process.stderr.write('`// phase-id-owner: <reason>` comment on the line directly above the regex.\n');
   process.stderr.write('`$((10#...))` base-10-forced shell arithmetic is banned outright in\n');
-  process.stderr.write('gsd-core/workflows/**/*.md and gsd-core/references/**/*.md — sanction with\n');
+  process.stderr.write('msd-core/workflows/**/*.md and msd-core/references/**/*.md — sanction with\n');
   process.stderr.write('`<!-- phase-id-owner: <reason> -->` on the line directly above.\n');
   process.stderr.write('The single-optional-dotted-segment phase regex `[0-9]+(\\.[0-9]+)?` (or its \\d\n');
-  process.stderr.write('near-variant) is banned outright in gsd-core/workflows/**/*.md,\n');
-  process.stderr.write('gsd-core/references/**/*.md, and agents/**/*.md — widen it to `*` (unbounded\n');
+  process.stderr.write('near-variant) is banned outright in msd-core/workflows/**/*.md,\n');
+  process.stderr.write('msd-core/references/**/*.md, and agents/**/*.md — widen it to `*` (unbounded\n');
   process.stderr.write('segments) or sanction with `<!-- phase-id-owner: <reason> -->`.\n');
   process.stderr.write('A digit-only unbounded-segment phase regex `[0-9]+(\\.[0-9]+)*` on the same roots\n');
   process.stderr.write('is missing the canonical letter axis (#4660) — widen to `[0-9]+[A-Z]?(\\.[0-9]+)*`\n');