fix(eslint): flatten oxlint config to resolve CI lint failure

[maruf-pfc]

Proposed Changes

• Fix ESLint flat config structure
• Resolve CI lint failure caused by nested config array
• Improve compatibility with oxlint + Vue config

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Description

This PR fixes an ESLint configuration issue that caused CI linting to fail with the error:

TypeError: Unexpected array

The issue occurred because pluginOxlint.configs['flat/recommended'] was added as a nested array instead of being spread into the root config.

By spreading the config (...pluginOxlint.configs['flat/recommended']), the flat config structure is corrected and ESLint runs successfully.

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Related Issues

Resolves # (add issue number if applicable)

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Checklist

• I have followed the [Contributing Guidelines](CONTRIBUTING.md).
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new linting errors.
• I have added tests that prove my fix is effective or that my feature works. (not required for config fix)
• New and existing unit tests pass locally with my changes.
• I have updated the documentation accordingly. (if needed)