Revert "Add Kiro IDE support (.kiro/) (#548)"

This reverts commit ce828c1c3c.

.kiro/steering/security.md

@@ -1,34 +0,0 @@
----
-inclusion: auto
-description: Security best practices including mandatory checks, secret management, and security response protocol.
----
-
-# Security Guidelines
-
-## Mandatory Security Checks
-
-Before ANY commit:
-- [ ] No hardcoded secrets (API keys, passwords, tokens)
-- [ ] All user inputs validated
-- [ ] SQL injection prevention (parameterized queries)
-- [ ] XSS prevention (sanitized HTML)
-- [ ] CSRF protection enabled
-- [ ] Authentication/authorization verified
-- [ ] Rate limiting on all endpoints
-- [ ] Error messages don't leak sensitive data
-
-## Secret Management
-
-- NEVER hardcode secrets in source code
-- ALWAYS use environment variables or a secret manager
-- Validate that required secrets are present at startup
-- Rotate any secrets that may have been exposed
-
-## Security Response Protocol
-
-If security issue found:
-1. STOP immediately
-2. Use **security-reviewer** agent
-3. Fix CRITICAL issues before continuing
-4. Rotate any exposed secrets
-5. Review entire codebase for similar issues