#3441 fix(annotations): allow hyphens in annotation names

Summary

• Widens the validation regex for Annotation.name from ^\w+$ to ^\w-$ so hyphenated names like my-annotation are accepted
• Regenerates protobuf code (Go), TypeScript definitions, and JSON Schema from the updated proto
• Adds documentation note about Go template index function syntax for hyphenated annotation access

Context

Fixes #3405 — annotation names with hyphens were rejected by validation.

Test plan

• Unit tests updated to cover hyphenated annotation names
• Protobuf regeneration verified (Go, TypeScript, JSON Schema)
• CI checks pass (block/protoc version compatibility)

Notes

Regenerates 33 files (mostly auto-generated protobuf artifacts). The source change is a 1-line regex widen in the proto definition + documentation.