fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/framework-migration/skills/dependency-upgrade/SKILL.md

@@ -366,64 +366,3 @@ npm install --workspaces
 # Update specific workspace
 npm install package@latest --workspace=packages/app
 ```
-
-## Resources
-
-- **references/semver.md**: Semantic versioning guide
-- **references/compatibility-matrix.md**: Common compatibility issues
-- **references/staged-upgrades.md**: Incremental upgrade strategies
-- **references/testing-strategy.md**: Comprehensive testing approaches
-- **assets/upgrade-checklist.md**: Step-by-step checklist
-- **assets/compatibility-matrix.csv**: Version compatibility table
-- **scripts/audit-dependencies.sh**: Dependency audit script
-
-## Best Practices
-
-1. **Read Changelogs**: Understand what changed
-2. **Upgrade Incrementally**: One major version at a time
-3. **Test Thoroughly**: Unit, integration, E2E tests
-4. **Check Peer Dependencies**: Resolve conflicts early
-5. **Use Lock Files**: Ensure reproducible installs
-6. **Automate Updates**: Use Renovate or Dependabot
-7. **Monitor**: Watch for runtime errors post-upgrade
-8. **Document**: Keep upgrade notes
-
-## Upgrade Checklist
-
-```markdown
-Pre-Upgrade:
-
-- [ ] Review current dependency versions
-- [ ] Read changelogs for breaking changes
-- [ ] Create feature branch
-- [ ] Backup current state (git tag)
-- [ ] Run full test suite (baseline)
-
-During Upgrade:
-
-- [ ] Upgrade one dependency at a time
-- [ ] Update peer dependencies
-- [ ] Fix TypeScript errors
-- [ ] Update tests if needed
-- [ ] Run test suite after each upgrade
-- [ ] Check bundle size impact
-
-Post-Upgrade:
-
-- [ ] Full regression testing
-- [ ] Performance testing
-- [ ] Update documentation
-- [ ] Deploy to staging
-- [ ] Monitor for errors
-- [ ] Deploy to production
-```
-
-## Common Pitfalls
-
-- Upgrading all dependencies at once
-- Not testing after each upgrade
-- Ignoring peer dependency warnings
-- Forgetting to update lock file
-- Not reading breaking change notes
-- Skipping major versions
-- Not having rollback plan