docs: add 'When to Activate' sections to 14 skill definitions

Add activation triggers to skills that were missing them, helping
Claude Code determine when to load each skill contextually.

skills/django-verification/SKILL.md

@@ -7,6 +7,14 @@ description: "Verification loop for Django projects: migrations, linting, tests
 
 Run before PRs, after major changes, and pre-deploy to ensure Django application quality and security.
 
+## When to Activate
+
+- Before opening a pull request for a Django project
+- After major model changes, migration updates, or dependency upgrades
+- Pre-deployment verification for staging or production
+- Running full environment → lint → test → security → deploy readiness pipeline
+- Validating migration safety and test coverage
+
 ## Phase 1: Environment Check
 
 ```bash