Walkthrough

Adds a canonicalization step that normalizes calc(...) expressions referencing the spacing variable into a spacing-function form. Implements calcToSpacingFunction and spacingCalcToSpacingFunction, integrates them into the utility canonicalization pipeline, and updates packages/tailwindcss/src/canonicalize-candidates.test.ts with new padding-related test cases covering standard and arbitrary-property patterns. Also adds a changelog entry noting the change.

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