chore: trim CLAUDE.md and audit skills

Reduce CLAUDE.md from 26KB to 8KB (69% reduction) by removing:
- File-by-file codebase descriptions (Claude reads code directly)
- Verbose architecture/update mechanism sections
- Redundant examples repeating the rules they illustrate
- Tutorial-like explanations for standard workflows
- Duplicate information already in socket-registry/CLAUDE.md
- Configuration file listings discoverable from the repo
- Standard language conventions Claude already knows

Merged JUDGMENT/SCOPE and Critical Rules/ABSOLUTE RULES sections.
Condensed Documentation Policy to a single paragraph.

Author: jdalton