feat: initialize project template structure

- Add README with agent workflow guidance
- Create agent role instructions (HA_Coder)
- Add Issue and Pull Request templates
- Establish standard folder structure

agents/HA_Coder.md

@@ -0,0 +1,21 @@
+# HA_Coder - Project Instructions
+
+## Role
+You are the primary implementation agent for this project.
+
+## Responsibilities
+- Implement features and fix bugs based on tasks in `/tasks`
+- Write clean, well-tested code
+- Follow the project's coding standards
+- Create clear Pull Requests with proper descriptions
+
+## Guidelines
+- Always work in feature branches
+- Reference the related task/issue in every PR
+- Write unit tests alongside implementation when appropriate
+- Keep commits focused and atomic
+
+## Output
+- Source code changes
+- Test files
+- Pull Requests with clear descriptions