feat: add metadata registry for buckets

[davidturnbull]

Problem

Bucket types (json, yaml, markdown, etc.) have different capabilities, but there was no programmatic way to query these capabilities. Questions like "which buckets support the [locale] placeholder?" or "which buckets support locked keys?" required manually reviewing loader implementations.

This made it difficult to:

• Generate accurate documentation
• Validate user configurations before instantiating loaders
• Build UI components that need to display bucket capabilities
• Understand bucket features without deep-diving into code

Solution

Added a metadata registry that explicitly declares capabilities for all 29 bucket types.

New Bucket Type

Each bucket now includes:

• displayName - Human-readable label (e.g., "JSON", "Xcode XCStrings")
• supportsFormatter - Can use code formatters (Prettier, etc.)
• supportsInjectLocale - Can inject locale code into content
• supportsLockedKeys - Supports locking specific translation keys
• supportsIgnoredKeys - Supports ignoring specific keys
• supportsLockedPatterns - Supports pattern-based locking (MDX only)
• supportsLocalePlaceholder - Supports [locale] placeholder in file paths
• createLoader() - Factory function to create the loader

Architecture

Moved from a large switch statement to a standalone registry approach:

export const BUCKETS: Record<string, Bucket> = {
  json: {
    displayName: "JSON",
    supportsFormatter: true,
    supportsLocalePlaceholder: true,
    // ... other capabilities
    createLoader: (ctx) => composeLoaders(...)
  },
  // ... all 29 bucket types
}

This approach was chosen because:

1. Lightweight consumption - Metadata can be imported without loader dependencies
2. Build-time usage - Documentation generation doesn't need full loader infrastructure
3. Clear separation - Metadata (declarative) is separate from loaders (runtime behavior)
4. Queryability - Easy to lookup by bucket type without function calls

Public API

• BUCKETS - Complete registry of all bucket types
• getBucket(type) - Helper to lookup a bucket by type
• Bucket type - For consumers who need the type definition

Impact

• No breaking changes - createBucketLoader() signature unchanged
• Enables future features like auto-generated documentation
• Makes bucket capabilities explicit and maintainable
• Simplifies validation and error messaging

🤖 Generated with Claude Code

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