fix(skills): add Anti-Patterns sections, fix descriptions, quality checks, and required inputs

- Add Anti-Patterns section (3-5 binary checkboxes) to all modified skills
- Fix Quality Checks to use binary checkbox format where needed
- Rewrite descriptions to verb-when-produces format where needed
- Add Required Inputs sections to skills missing them
- Fix email-triage frontmatter YAML quoting

https://claude.ai/code/session_01MuGKn3a3Gbqoe8uM5Lmuqt

skills/competitor-teardown/SKILL.md

@@ -70,6 +70,13 @@ Produce a clean SWOT for the user's product in the context of this competitive l
 - [ ] SWOT is honest — Weaknesses and Threats should not be softened
 - [ ] Recommendations are specific and actionable, not generic strategy advice
 
+## Anti-Patterns
+
+- [ ] Do not mark feature presence as equivalent across competitors without noting quality differences — both products may have "reporting" while one's is meaningfully better
+- [ ] Do not position the user's product in the most favourable quadrant without justification — a self-serving positioning map that ignores real competitive pressure provides no strategic value
+- [ ] Do not soften Weaknesses or Threats in the SWOT — a SWOT that only celebrates strengths is a marketing document, not a strategy tool
+- [ ] Do not include unverifiable claims about competitor capabilities without flagging them as assumptions — presenting rumours as facts damages analytical credibility
+
 ## Example Trigger Phrases
 
 - "Do a competitor analysis of [Product] vs [Competitor A] and [Competitor B]"