Remove per-workflow FIELD_REFERENCE.md files

[jwm4]

Summary

The FIELD_REFERENCE.md files in individual workflows are redundant and should be removed.

Affected files:

• workflows/triage/FIELD_REFERENCE.md
• workflows/cve-fixer/FIELD_REFERENCE.md

Why remove them

• Generic ambient.json field docs (name, description, systemPrompt, etc.) are redundant with the central AMBIENT_JSON_SCHEMA.md
• Workflow-specific content (e.g. triage recommendation types, output formats) is duplicated from the systemPrompt or would be better placed in the workflow's README or inline in templates
• Maintenance burden: every schema change (like Fix ambient.json field documentation to match platform #92) requires updating these per-workflow copies, and they drift — the cve-fixer version still documented fictional fields (version, author, tags, icon) that don't exist in the platform
• Generated boilerplate: these were produced by the workflow-creator skill template, not written intentionally

Suggested approach

1. Remove both FIELD_REFERENCE.md files
2. Move any genuinely workflow-specific documentation into the workflow's README.md if not already covered there
3. Consider removing the FIELD_REFERENCE.md template from the workflow-creator skill so new workflows don't generate them

This issue was created by Claude Code under the supervision of Bill Murdock.