Parallel mock implementation

This is a building block, not a standalone bring-up workflow. Invoke it as part of /implement-mock or /compute-llk-bringup when the work-list is large enough to amortize the dispatch overhead.

When to use

• ≥4 similar files to author (e.g. a batch of SFPU shims, a sweep of missing NOC overloads, a fanout of fabric primitives).
• Each output is independent — one file per worker, no shared edits, no read dependencies between workers.

Don't use it for:

• Single-file work — call the worker prompt directly inline.
• Cross-cutting wiring that touches a shared file (e.g. one sfpu_split_includes.h, one .claude/references/structure.yaml). The orchestrator handles those centrally after workers return.