feat: add Breakdown connectivity skill

[grid-breakdown]

Summary

• add an evidence-first Breakdown connectivity troubleshooting skill
• include the canonical setup helper and MCP tool reference
• add OpenAI agent metadata and generated skill index entry

Validation

• npm run skill:validate
• npm run build
• canonical setup helper and MCP reference match the source repository

Breakdown is a macOS connectivity diagnostic tool published by PeaceCraft. The skill helps agents distinguish local network, Internet-path, DNS, and app/service failures before recommending remediation.

[github-actions]

🔒 PR Risk Scan Results

Scanned 4 changed file(s).

Severity	Count
🔴 High	0
🟠 Medium	0
ℹ️ Info	1

Severity	Rule	File	Line	Match
ℹ️	skill-script-touched	skills/breakdown-connectivity/scripts/setup-breakdown.sh	1	skills/breakdown-connectivity/scripts/setup-breakdown.sh

This is an automated soft-gate report. Findings indicate review targets and do not block merge by themselves.

[github-actions]

🔍 Vally Lint Results

✅ All checks passed

Scope	Checked
Skills	1
Agents	0
Total	1

Severity	Count
❌ Errors	0
⚠️ Warnings	0
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	✅ breakdown-connectivity (2/2 checks passed)
ℹ️	✓ [spec-compliance] All 1 skill(s) are spec-compliant.
ℹ️	✓ spec-compliance: All spec checks passed.
ℹ️	✓ [valid-refs] All file references across 1 skill(s) are valid.
ℹ️	✓ valid-refs: All file references resolve to existing files within the skill directory.
ℹ️	1 skill(s) linted, 1 passed

Full linter output

### Linting skills/breakdown-connectivity
✅ breakdown-connectivity (2/2 checks passed)
    ✓ [spec-compliance] All 1 skill(s) are spec-compliant.
        ✓ spec-compliance: All spec checks passed.
    ✓ [valid-refs] All file references across 1 skill(s) are valid.
        ✓ valid-refs: All file references resolve to existing files within the skill directory.

1 skill(s) linted, 1 passed

[aaronpowell]

Overly specific MacOS only tool means this is ill suited for the repo.