feat(config): add global productAttributes and contentAttributes sections

[mariobrgomes]

Summary

Add new productAttributes and contentAttributes config sections that allow defining shared attributes once and referencing them across product types and model types.

Key Changes

• New config sections: productAttributes for PRODUCT_TYPE attributes, contentAttributes for PAGE_TYPE attributes
• AttributeCache: In-memory cache for O(1) attribute lookup during deployment
• Preflight validation: Rejects inline attribute definitions with migration guidance
• Introspect: Automatically extracts attributes into separate sections by type
• Validation errors: "Did you mean?" suggestions using Levenshtein distance for typos
• Diff engine: Shows changes under "Product Attributes" and "Content Attributes" headers
• Backward compatibility: Legacy attributes section still works with deprecation warning

Example Config

productAttributes:
  - name: Color
    inputType: DROPDOWN
    values:
      - name: Red
      - name: Blue

contentAttributes:
  - name: Author
    inputType: PLAIN_TEXT

productTypes:
  - name: T-Shirt
    productAttributes:
      - attribute: Color  # Reference by name

Test plan

• Unit tests for AttributeCache (18 tests)
• Unit tests for global attributes schema (discriminated unions)
• Unit tests for inline attribute detection (29 tests)
• Unit tests for validation errors with Levenshtein distance (20 tests)
• Unit tests for diff comparator with new entity types (9 tests)
• E2E: introspect → deploy → deploy (idempotent) → diff (no changes)

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[changeset-bot]

🦋 Changeset detected

Latest commit: 3fb2c70

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[peelar]

Let's make sure to add it to example.yml and README.md.