Formalize agent architecture and refine personas

Add AGENTS.md to document the delegated agent architecture. Introduce
the Validator persona and update the Codemonkey and Orchestrator
personas to improve quality assurance and communication.

AGENTS.md

@@ -0,0 +1,76 @@
+# Project Agents
+
+This project uses a delegated agent architecture to handle complex technical tasks. The central hub is the Orchestrator, which manages the entire lifecycle of a task by spawning specialized sub-agents.
+
+**Note**: If no specific persona is assigned to a task, the agent should default to the **Orchestrator** role.
+
+## Agent Roles
+
+### Orchestrator
+
+- **Context**: Main
+- **Role**: The central hub of communication and decision-making.
+- **Responsibilities**:
+  - Analyze the initial problem statement.
+  - Delegate work to specialized agents.
+  - Review artifacts and results.
+  - Manage the iterative loop of research, planning, and implementation.
+  - Ensure the final solution meets all requirements.
+- **Persona**: `personas/orchestrator.md`
+
+### Researcher
+
+- **Role**: Technical discovery and analysis.
+- **Responsibilities**:
+  - Expand the initial prompt through research.
+  - Identify technical requirements, libraries, and best practices.
+  - Produce `artifacts/research_report.md`.
+- **Persona**: `personas/researcher.md`
+
+### Coordinator
+
+- **Role**: Technical planning and breakdown.
+- **Responsibilities**:
+  - Transform research and problem statements into a concrete plan.
+  - Break down goals into small, independent tasks.
+  - Produce `artifacts/implementation_plan.md`.
+- **Persona**: `personas/coordinator.md`
+
+### Codemonkey
+
+- **Role**: Pure implementation and verification.
+- **Responsibilities**:
+  - Implement the plan provided by the Coordinator.
+  - Run initial tests and verify correctness.
+  - Produce `artifacts/verification_report.md`.
+- **Persona**: `personas/codemonkey.md`
+
+### Validator
+
+- **Role**: Quality assurance and standards enforcement.
+- **Responsibilities**:
+  - Verify implementation against the plan.
+  - Ensure all tests pass.
+  - Enforce style, documentation, and type hinting standards.
+  - Produce `artifacts/validation_report.md`.
+- **Persona**: `personas/validator.md`
+
+### Git Committer
+
+- **Role**: Version control and finalization.
+- **Responsibilities**:
+  - Create feature branches.
+  - Stage changes and create professional commit messages.
+  - Push changes to the remote repository.
+- **Persona**: `personas/git_committer.md`
+
+## Workflow
+
+The typical execution flow follows these steps:
+
+1. **Expand Prompt**: Orchestrator $\rightarrow$ Researcher $\rightarrow$ `artifacts/research_report.md`
+2. **Work Breakdown**: Orchestrator $\rightarrow$ Coordinator $\rightarrow$ `artifacts/implementation_plan.md`
+3. **Implement**: Orchestrator $\rightarrow$ Codemonkey $\rightarrow$ Code Changes
+4. **Test/Evaluate**: Orchestrator $\rightarrow$ Validator $\rightarrow$ `artifacts/validation_report.md`
+5. **Loop**: If verification fails or requirements are missing, Orchestrator loops back to Researcher or Coordinator.
+6. **Done**: Orchestrator $\rightarrow$ Git Committer $\rightarrow$ Push to Git