Add context: fork option to systematic-debugging skill

[holstein13]

Summary

Add support for context: fork to the systematic-debugging skill, allowing its heavy 4-phase investigation process to run in an isolated sub-agent context.

Background

The systematic-debugging skill is one of the most investigation-heavy skills in the library:

• 4 rigorous phases: Root Cause Investigation → Pattern Analysis → Hypothesis Testing → Implementation
• 11 supporting files: root-cause tracing, defense-in-depth, condition-based waiting, test scenarios, etc.
• Extensive exploration: reading errors, git diffs, stack traces, running diagnostics, comparing code patterns
• Scientific method enforcement: hypothesis forming, minimal testing, verification loops

Why Fork Would Benefit This Skill

Token efficiency:

• Investigation involves many file reads, grep searches, git operations
• Evidence gathering (logging component boundaries, tracing data flow) produces verbose output
• Failed hypotheses and their tests consume tokens but aren't needed afterward

Context cleanliness:

• The investigation journey (hypotheses tried, evidence gathered, dead ends) pollutes main context
• The investigation result (root cause identified, fix verified) is what matters for subsequent work
• Main session stays focused on implementation rather than debugging archaeology

Clean handoff:

• When debugging completes, return to main context with:
  • Root cause summary
  • The fix applied
  • Test verification
• Not the full trail of hypothesis → test → fail → new hypothesis loops

Proposed Change

Add context: fork to the skill frontmatter:

---
name: systematic-debugging
description: Use when encountering any bug, test failure, or unexpected behavior
context: fork
---

Considerations

• Users may sometimes want to see the full investigation trail in main context
• Could be made configurable (fork by default, with option to run inline)
• Related skill superpowers:test-driven-development referenced in Phase 4 would need coordination if both fork

Related

• Issue #245 (context: fork for brainstorming skill)
• Claude Code CLI 2.1.2 fork feature