dsh-agent-driver-writehere: Integrate the WriteHERE long-form writing loop as DeepSeek Harness's second reasoning loop.

# Introduction Building a long-form writing agent on DeepSeek Harness (hereinafter DSH) typically involves encapsulating retrieval, drafting, and revision into a set of tools attached to the default ReAct loop. This approach squeezes the outline, draft, and revision into a single loop, leaving no dedicated space for different types of work and lacking independent handling for mid-process modifications. `dsh-agent-driver-writehere` adopts a different mounting point: instead of appending tools to the default loop, it implements the WriteHERE long-form writing loop (heterogeneous recursive planning) as an agent driver, running as a second inference loop. The following sections introduce its design, installation, and usage. # What is dsh-agent-driver