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/api-scaffolding/skills/fastapi-templates/SKILL.md

@@ -538,30 +538,3 @@ async def test_create_user(client):
     assert data["email"] == "test@example.com"
     assert "id" in data
 ```
-
-## Resources
-
-- **references/fastapi-architecture.md**: Detailed architecture guide
-- **references/async-best-practices.md**: Async/await patterns
-- **references/testing-strategies.md**: Comprehensive testing guide
-- **assets/project-template/**: Complete FastAPI project
-- **assets/docker-compose.yml**: Development environment setup
-
-## Best Practices
-
-1. **Async All The Way**: Use async for database, external APIs
-2. **Dependency Injection**: Leverage FastAPI's DI system
-3. **Repository Pattern**: Separate data access from business logic
-4. **Service Layer**: Keep business logic out of routes
-5. **Pydantic Schemas**: Strong typing for request/response
-6. **Error Handling**: Consistent error responses
-7. **Testing**: Test all layers independently
-
-## Common Pitfalls
-
-- **Blocking Code in Async**: Using synchronous database drivers
-- **No Service Layer**: Business logic in route handlers
-- **Missing Type Hints**: Loses FastAPI's benefits
-- **Ignoring Sessions**: Not properly managing database sessions
-- **No Testing**: Skipping integration tests
-- **Tight Coupling**: Direct database access in routes