fix(lsp): ESLint LSP server fails to auto-install on Windows

[fraineralex]

Summary

• Use npm.cmd instead of npm on Windows for running install and compile commands during ESLint LSP server installation
• Remove invalid --max-old-space-size V8 flag (Bun uses JavaScriptCore, not V8)

Problem

On Windows, npm is actually npm.cmd (a batch file wrapper). Bun's shell may not correctly resolve bare npm commands, causing the ESLint server installation to fail silently.

Additionally, the --max-old-space-size=8192 flag is a V8/Node.js flag, but Bun uses JavaScriptCore. This flag is ignored or could cause unexpected behavior.

Solution

const npmCmd = process.platform === "win32" ? "npm.cmd" : "npm"
await $`${npmCmd} install`.cwd(finalPath).quiet()
await $`${npmCmd} run compile`.cwd(finalPath).quiet()

This follows the same pattern used by other LSP implementations in the codebase (e.g., Oxlint at line 232-234).

Fixes #6365