Excavate

Recover what a legacy repo already knows about itself before the first feature runs blind on it. The output is an off-tree dossier (hotspots, coupling, recovered decisions, a who-to-ask map, and a Coverage block saying what the history could and could not tell you) plus an opt-in PR of docs/solutions/ entries in /compound's format, so /research, /write-a-prd, and /execute read them through the keyword grep they already run.

Two things keep this honest. Tornhill's method mines version control as a behavioral record: a hotspot is the intersection of change frequency and complexity, neither axis alone, bounded to a fixed window, and it is a probability to inspect, not a verdict to act on. And the Grounding Rule (references/visual-rendering-core.md § 1) splits every artifact: SHAs, PR numbers, paths, counts, and quoted rationale are copied from git and gh output, never retyped; the model writes only the prose around them. A decision whose "why" is the model's guess is not recovered, it is invented, and it stays out of the repo.