chore: rebrand to GSD-redux/get-shit-done-redux

Mirror of code, issues, and PRs from the upstream gsd-build/get-shit-done,
which appears compromised or abandoned (maintainer unreachable since
2026-04-01; $GSD token linked to rug-pull).

- Adds rebrand notice block at top of English README
- Removes $GSD token badge and @gsd_foundation X badge (keeps Discord)
- Renames npm packages: get-shit-done-cc -> get-shit-done-redux,
  @gsd-build/sdk -> @gsd-redux/sdk
- Updates all repo URLs across docs, workflows, package.json, bin/
- Updates ci@gsd-build -> ci@gsd-redux in workflow git identities
- Leaves CHANGELOG and .changeset/* alone (historical, time-stamped)

hooks/gsd-check-update-worker.js

@@ -90,7 +90,7 @@ if (configDir) {
 
 let latest = null;
 try {
-  latest = execFileSync('npm', ['view', 'get-shit-done-cc', 'version'], {
+  latest = execFileSync('npm', ['view', 'get-shit-done-redux', 'version'], {
     encoding: 'utf8',
     timeout: 10000,
     windowsHide: true,