fix: Add missing required sections to 28 non-compliant skills

[mcj-coder]

Summary

The skill structure validation script identifies 28 skills missing required sections per SKILL-FORMAT.md.

Validation Output

45 validation errors across 28 skills:
- 16 skills missing both "When to Use" and "Core Workflow"
- 8 skills missing only "Core Workflow"
- 4 skills missing only "When to Use"
- 1 skill missing "Overview", "When to Use", and "Core Workflow"

Acceptance Criteria

• All 28 skills have required sections added (PR #391)
• npm run validate:skills passes (0 errors)
• npm run lint passes
• Content is meaningful (not placeholder text)

Skills Fixed

Missing Overview + When to Use + Core Workflow (1)

• dotnet-logging-serilog

Missing When to Use + Core Workflow (15)

• agent-workitem-automation
• csharp-best-practices
• dotnet-bespoke-code-minimisation
• dotnet-domain-primitives
• dotnet-efcore-practices
• dotnet-healthchecks
• dotnet-mapping-standard
• dotnet-open-source-first-governance
• dotnet-source-generation-first
• dotnet-specification-pattern
• dotnet-testing-assertions
• innersource-governance-bootstrap
• observability-logging-baseline
• security-processes
• testing-strategy-dotnet

Missing only Core Workflow (8)

• broken-window
• dotnet-best-practices
• finishing-a-development-branch
• pair-programming
• persona-switching
• safe-brownfield-refactor
• scoped-colocation
• testing-strategy-agnostic

Missing only When to Use (4)

• agents-onboarding
• component-boundary-ownership
• process-skill-router
• requirements-gathering

References

• Validation script: scripts/validate-skill-structure.cjs
• Format spec: docs/SKILL-FORMAT.md

[mcj-coder]

Plan

Simple bulk fix - add the missing sections to each non-compliant skill:

1. Run npm run validate:skills to get list of non-compliant skills
2. For each skill, read existing content and add missing sections:
   • Overview: 2-4 sentences about purpose (if missing)
   • When to Use: Bullet list of trigger conditions (if missing)
   • Core Workflow: Numbered steps for primary workflow (if missing)
3. Verify all 55 skills pass validation
4. Run lint to ensure formatting is correct
5. Commit and create PR

No architectural decisions required - following existing SKILL-FORMAT.md spec.

Plan approved. Proceeding with implementation.