feat(rule): no-string-interpolation

[angelos24]

add no-string-interpolation rule

Description

This PR introduces a new ESLint rule no-string-interpolation designed to prevent dynamic
Tailwind class construction. Tailwind CSS relies on static analysis to generate CSS, and
constructing class names via string interpolation (e.g., bg-${color}) prevents the
compiler from identifying used classes.

The rule specifically targets class and className attributes in JSX and reports instances
where an interpolated value is directly attached to a string literal without a space
delimiter.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

The changes were verified by adding a comprehensive test suite in
tests/lib/rules/no-string-interpolation.js.

• Test A: Verified that partial string interpolation like bg-${color} or ${variant}-text
  is correctly flagged as an error.
• Test B: Confirmed that full variable interpolation (e.g., ${color} text-lg)
  remains valid, as it doesn't involve dynamic construction of a specific Tailwind
  utility name.

Test Configuration:

Test Configuration:

• OS + version: Linux
• NPM version: 10.x (as per environment)
• Node version: 18.x/20.x/22.x/24.x

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings