CLI runs on Node 20+: npx storebound (bunx keeps working)

- cli/lib/rt.ts: the runtime layer on node: modules (spawn / spawnSync with Bun's defaults, exit codes and
  "Executable not found", which with PATHEXT, sleep, serve, Glob, hasher, gunzip, stdin, SQLite, packageRoot,
  config imports with a type-stripping fallback for Node 20); every Bun.* use in cli/ goes through it
- tools/gen-embedded.ts -> cli/lib/embedded.ts: templates/, cli/shots/*.html and Play's Data safety form embedded
  (replaces Bun text imports; the bundle and the compiled sidecar carry them), checked fresh by bun run ci
- package.json: bin dist/storebound.mjs (Node ESM bundle, tools/build-node.ts, prepack), engines node >=20
- bun run ci: node bundle + node smoke (real node: --version, help, check same as Bun, scan, release plan --help,
  init, MCP handshake + tool call); Forgejo CI sets up Node 20; tests/node-compat.test.ts guards cli/
- install writes npx MCP commands when run with Node; bin/storebound falls back to Node
- docs: npx storebound init (Node 20+) or bunx storebound init

cli/play/client.ts

@@ -4,6 +4,7 @@ import { tokenSource } from '../lib/google-auth';
 import { log, warn } from '../lib/log';
 import { errorBody } from '../lib/http';
 import { AmbiguousWriteError, isAmbiguous, retrySafe } from '../lib/upsert';
+import * as rt from '../lib/rt';
 
 export type PlayClient = Awaited<ReturnType<typeof playClient>>;
 
@@ -30,13 +31,13 @@ export async function playClient(root: string, packageName: string) {
           body: body === undefined ? undefined : bin ? (body as unknown as BodyInit) : JSON.stringify(body),
         });
       } catch (e) {
-        if (safe && attempt < 4) { await Bun.sleep(2000 * (attempt + 1)); continue; }
+        if (safe && attempt < 4) { await rt.sleep(2000 * (attempt + 1)); continue; }
         if (!safe) throw new AmbiguousWriteError(`${method} ${short()} -> no answer (${(e as Error).message})`);
         throw e;
       }
       const text = await r.text();
       if (r.ok) return (text ? JSON.parse(text) : {}) as T;
-      if ((r.status === 429 || (r.status >= 500 && safe)) && attempt < 4) { await Bun.sleep(2000 * (attempt + 1)); continue; }
+      if ((r.status === 429 || (r.status >= 500 && safe)) && attempt < 4) { await rt.sleep(2000 * (attempt + 1)); continue; }
       // A wrong path casing answers with an HTML 404 page, not JSON: say so instead of dumping the HTML.
       const msg = /^\s*</.test(text) ? `(HTML ${r.status} page: wrong path or casing?)` : errorBody(text);
       if (r.status >= 500 && !safe) throw new AmbiguousWriteError(`${method} ${short()} -> ${r.status} ${msg}`, r.status);