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)

tests/bug-2649-sdk-fail-fast.test.cjs

@@ -35,7 +35,7 @@ function loadInstaller() {
 function makeTempSdk({ npxCache = false } = {}) {
   let root;
   if (npxCache) {
-    root = path.join(os.tmpdir(), `gsd-npx-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, 'npm-cache', '_npx', 'deadbeefcafe0001', 'node_modules', 'get-shit-done-cc');
+    root = path.join(os.tmpdir(), `gsd-npx-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, 'npm-cache', '_npx', 'deadbeefcafe0001', 'node_modules', 'get-shit-done-redux');
     fs.mkdirSync(root, { recursive: true });
   } else {
     root = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-clone-'));
@@ -155,7 +155,7 @@ describe('installer SDK dist-missing fail-fast (#2649)', () => {
       assert.strictEqual(ir.reason, 'sdk_fail_fast');
       assert.strictEqual(ir.context, 'npx-cache');
       assert.strictEqual(ir.missing_artifact, 'sdk/dist');
-      assert.strictEqual(ir.fix_command, 'npm install -g get-shit-done-cc@latest');
+      assert.strictEqual(ir.fix_command, 'npm install -g get-shit-done-redux@latest');
       assert.strictEqual(ir.attempted_nested_install, false,
         'IR contract: nested-install must always be false (this is a hard invariant)');
     } finally {