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

This reverts commit ce828c1c3c.

.kiro/steering/development-workflow.md

@@ -1,34 +0,0 @@
----
-inclusion: auto
-description: Development workflow guidelines for planning, TDD, code review, and commit pipeline
----
-
-# Development Workflow
-
-> This rule extends the git workflow rule with the full feature development process that happens before git operations.
-
-The Feature Implementation Workflow describes the development pipeline: planning, TDD, code review, and then committing to git.
-
-## Feature Implementation Workflow
-
-1. **Plan First**
-   - Use **planner** agent to create implementation plan
-   - Identify dependencies and risks
-   - Break down into phases
-
-2. **TDD Approach**
-   - Use **tdd-guide** agent
-   - Write tests first (RED)
-   - Implement to pass tests (GREEN)
-   - Refactor (IMPROVE)
-   - Verify 80%+ coverage
-
-3. **Code Review**
-   - Use **code-reviewer** agent immediately after writing code
-   - Address CRITICAL and HIGH issues
-   - Fix MEDIUM issues when possible
-
-4. **Commit & Push**
-   - Detailed commit messages
-   - Follow conventional commits format
-   - See the git workflow rule for commit message format and PR process