Export ReadyCMD class (#992)

for building type-safe wrappers around .setStartCmd/.setReadyCmd

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Expose `ReadyCmd` via JS (`packages/js-sdk/src/index.ts`) and Python
(`e2b/__init__.py`) SDK entrypoints, with patch version bumps.
> 
> - **SDK Exports**:
> - **JS**: Re-exports `ReadyCmd` from `./template/readycmd` in
`packages/js-sdk/src/index.ts`.
> - **Python**: Exposes `ReadyCmd` in `e2b/__init__.py` imports and
`__all__`.
> - **Versioning**:
> - `.changeset/early-trainers-repeat.md`: Patch bumps for
`@e2b/python-sdk` and `e2b`.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
ff91a3e. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: mishushakov

.changeset/early-trainers-repeat.md

@@ -0,0 +1,6 @@
+---
+'@e2b/python-sdk': patch
+'e2b': patch
+---
+
+export ReadyCmd class

packages/js-sdk/src/index.ts

@@ -67,6 +67,7 @@ export default Sandbox
 export * from './template'
 
 export {
+  ReadyCmd,
   waitForPort,
   waitForURL,
   waitForProcess,

packages/python-sdk/e2b/__init__.py

@@ -85,6 +85,7 @@
 )
 from .template.main import TemplateBase, TemplateClass
 from .template.readycmd import (
+    ReadyCmd,
     wait_for_file,
     wait_for_url,
     wait_for_port,
@@ -149,6 +150,7 @@
     "TemplateBase",
     "TemplateClass",
     "CopyItem",
+    "ReadyCmd",
     "wait_for_file",
     "wait_for_url",
     "wait_for_port",