feat: Implement Plan-and-Reflect Autonomous Loop

[Gdub662]

This commit introduces a significant architectural enhancement to the Bytebot agent, moving it from a purely reactive model to a proactive, plan-driven autonomous system.

The core changes include:

1. PlannerService: A new service that uses an LLM to break down high-level user requests into a concrete, step-by-step plan.

2. ReflectorService: A new service that evaluates the outcome of each executed step. It determines if a step was successful, failed, or needs to be retried, enabling self-correction.

3. Plan-and-Execute Loop: The AgentProcessor has been refactored to orchestrate the new autonomous loop. It now generates a plan, executes it step-by-step, and reflects on each outcome to decide the next action.

4. Database Schema: The Task model in the Prisma schema has been updated to store the plan and the current planStep, making the agent's state more robust and resumable.

5. Testing:

   • The Jest configuration has been fixed to work correctly in the monorepo environment.
   • A new unit test for the PlannerService has been added, which uncovered and led to a fix for a bug in handling empty LLM responses.

This new architecture provides a strong foundation for future autonomous capabilities, such as more advanced planning, memory, and self-optimization.