feat: Add write_script and read_script tools for script management

[kevinswint]

Summary

This PR adds MCP tools for reading and writing script source code:

• write_script - Creates or updates Script, LocalScript, or ModuleScript with provided Luau source
• read_script - Reads source code from existing scripts (enables diff/patch workflows)

Both tools use ScriptEditorService for safe, Studio-integrated script access.

Motivation

AI assistants need to both read existing code (to understand before modifying) and write new code. The run_code tool can execute Luau but cannot access script source directly due to Roblox security restrictions.

ScriptEditorService provides the officially supported methods:

• UpdateSourceAsync() for writing
• GetEditorSource() for reading

Changes

Rust Server:

• Added WriteScript and ReadScript structs
• Added tool functions for both operations

Plugin:

• WriteScript.luau - Creates scripts, handles nested paths, writes source
• ReadScript.luau - Navigates to script, reads source with metadata

Types:

• Added WriteScriptArgs and ReadScriptArgs type definitions

Test plan

• Create a Script in ServerScriptService
• Create nested paths with automatic folder creation
• Update existing script source
• Read script source back and verify content
• Verify metadata (type, path, char count, line count)

Example Usage

-- Write a script
write_script({
  path: "ServerScriptService.GameManager",
  source: "print('Hello from MCP!')"
})

-- Read it back
read_script({
  path: "ServerScriptService.GameManager"
})
-- Returns: [SUCCESS] Script at ServerScriptService.GameManager (25 characters, 1 lines)
-- print('Hello from MCP!')

🤖 Generated with Claude Code

[Shchvova]

Hi! We added community contribution guidelines to help us triage and accept PRs.

This PR adds several tools which would be better described as tools executed with run_code. MCP tools are added to each LLM request consuming tokens. We tested and found that all LLMS can crate scripts with Instance.new() and set/read sources with .Source property.

Thank you for understanding!