feat: support evaluating scripts from local files

[achideal]

Summary

• extend evaluate_script with sourcePath for loading JavaScript from the MCP server filesystem
• add format: function | script while preserving existing function calls, output redirection, and CLI positional syntax
• validate local source paths through MCP roots and cover page, service worker, and CLI execution

Supersedes #1772.
Fixes #1775.

Test plan

• npm run gen
• npm run test tests/tools/script.test.ts tests/e2e/chrome-devtools-commands.test.ts
• npm run test (feature-related tests pass; the local Windows run has unrelated existing failures: symlink creation requires additional OS privileges, one extension-page timeout, and the large full-page screenshot exceeds Chrome's limit)

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