AI/Infra: Implement opening book integration for faster responses

[chinweobtagaz]

Description

Calculating standard opening theory (e.g., the Ruy Lopez) from scratch wastes immense GPU/CPU resources and slows down initial bot response times.

What Needs to be Done

• Integrate a Polyglot .bin opening book reader into the worker pipeline.
• If the current FEN exists in the book, return the book move immediately.
• Fallback to full engine search if out of book.

Acceptance Criteria

• First 10-15 moves of standard openings evaluate in <5ms.
• Bot plays varied, theoretically sound openings based on book weights.
• Server CPU load significantly reduced during the opening phase of games.