- feature: mount in host runner

[agallardol]

Add support for mounting files and passing environment variables to Deno runner

This PR introduces several enhancements to the Deno runner in the shinkai-tools-runner library:

1. Added support for mounting files with read/write and read-only permissions into the Deno execution environment. This allows tools to access specific files during execution.

2. Implemented passing of environment variables to the Deno runner, including MOUNT, ASSETS, and HOME. These environment variables provide information about the mounted files and directories to the running tool.

3. Enhanced the Deno permissions system to grant appropriate access to mounted files, assets, and necessary directories for Playwright/Chrome.

4. Updated the example usage in the README to demonstrate how to set up and call a Shinkai tool from Rust, including passing input data, handling output, and specifying mounted files.

5. Improved logging and error handling in the DenoExecutionStorage and DenoRunner modules.

6. Renamed the assets field in the ExecutionContext struct to assets_files for clarity.

These changes improve the flexibility and usability of the shinkai-tools-runner library by allowing tools to access specific files and directories during execution. The updated example in the README provides a clear guide on how to leverage these new features when calling Shinkai tools from Rust.