chore(#518): rename npm package + bin to @opengsd/gsd-core (#519)

* chore: rename npm package + bin to @opengsd/gsd-core (functional)

- package.json: name @opengsd/get-shit-done-redux → @opengsd/gsd-core,
  bin key get-shit-done-redux → gsd-core, repository/homepage/bugs URLs
- package-lock.json: regenerated (npm install --package-lock-only)
- tests/**, scripts/**, bin/**, .github/**, agents/**, commands/**,
  get-shit-done/bin/**, get-shit-done/workflows/**:
  applied the 4-rule replacement (scoped npm ref, GitHub repo path,
  bin/clone invocations) per #505 single-source refactor

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: sweep live references to @opengsd/gsd-core

Update all live documentation (README.md + translations, docs/**,
CONTRIBUTING.md, VERSIONING.md, SECURITY.md, CONTEXT.md,
docs/CANARY.md) to reflect the renamed package and repository.

Rules applied:
- @opengsd/get-shit-done-redux → @opengsd/gsd-core (scoped npm name)
- open-gsd/get-shit-done-redux → open-gsd/gsd-core (GitHub repo)
- GSD-redux/get-shit-done-redux → open-gsd/gsd-core (stale badge org)
- bare bin/clone refs → gsd-core

CHANGELOG.md, docs/adr/**, docs/RELEASE-*.md, docs/research/**,
and .changeset/** are preserved byte-identical.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* fix: add negative lookbehind to slash-command regex in bug-2954 test

The extractSlashReferences regex matched /gsd-core inside npm package
URLs (@opengsd/gsd-core), producing a false /gsd:core command reference.
Adding a negative lookbehind (?<![a-z]) excludes matches preceded by a
letter, so only standalone /gsd-<cmd> and /gsd:<cmd> tokens are found.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#518): add changeset for package rename

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* test(#518): update package-identity expectations to the renamed coordinates

The rebase regenerated the seam to @opengsd/gsd-core (bin gsd-core, repo
open-gsd/gsd-core). The #498 seam tests assert deriveIdentity against the REAL
package.json, so their expected literals must follow the rename. The drift-lint
unit test is left as-is — its SEAM is a self-consistent fixture and its
stale-literal detection cases would shift if altered; the live-repo scan in it
already passes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

scripts/release-tarball-smoke.cjs

@@ -28,7 +28,7 @@
  *     - Assert commands/gsd/<cmd>.md exists in the installed package
  *     - Parse the .md for a workflow @-import or inline reference
  *     - Assert the referenced workflow .md exists in the installed package
- *   If 'init' is in lifecycleCommands, runs `get-shit-done-redux --local --claude`
+ *   If 'init' is in lifecycleCommands, runs `gsd-core --local --claude`
  *   in fixtureDir to verify the installer is callable (INIT_FAILED on crash).
  *   Non-interactive: --local --claude flags skip all prompts.
  *
@@ -118,7 +118,7 @@ function binInvocation(binPath, args = []) {
 // ---------------------------------------------------------------------------
 
 /**
- * Locate the lib/node_modules/@opengsd/get-shit-done-redux package root inside
+ * Locate the lib/node_modules/@opengsd/gsd-core package root inside
  * an npm --prefix install directory.
  */
 function pkgRoot(installPrefix) {
@@ -167,10 +167,10 @@ function findGsdToolsBin(installPrefix) {
 }
 
 /**
- * Locate the get-shit-done-redux installer binary (the symlink in <prefix>/bin/).
+ * Locate the gsd-core installer binary (the symlink in <prefix>/bin/).
  */
 function findInstallerBin(installPrefix) {
-  for (const c of binCandidates(installPrefix, 'get-shit-done-redux')) {
+  for (const c of binCandidates(installPrefix, 'gsd-core')) {
     if (fs.existsSync(c)) return c;
   }
   return null;
@@ -390,7 +390,7 @@ function runSmoke({
         code: SMOKE.INIT_FAILED,
         details: {
           ...details,
-          reason: 'get-shit-done-redux binary not found in installPrefix',
+          reason: 'gsd-core binary not found in installPrefix',
           installPrefix,
         },
       };