feat(catalog): extend plugin capability metadata - #336

Summary

• extend plugin.json and schema-3 catalogs with validated localized product, discovery, requirement, privacy, action, setup, and relationship metadata
• publish complete metadata for the official plugin set while keeping machine-local dynamic actions out of signed catalogs
• enforce source and packaged runtime envelopes, preserve explicit PluginKit v3/v4 local-debug compatibility, and fail closed on malformed catalog fields
• align runtime action permissions and Finder-extension setup with manifest declarations
• predeclare the schema-3 host compatibility line as MacTools 1.2.1

Validation

• three-agent final branch review, including remediation verification
• full serial Xcode test suite
• full Python script suite: 125 tests
• focused post-remediation manifest, copy, sync, and compatibility suite: 59 tests
• JSON validation for all 52 plugin manifests plus the schema
• git diff --check

Closes #310