Implement the cached-main overlay: promoted notes, workflows, tests, branch heuristics, model/cache policies, and prompt patches warm future runs without mutating Git main.
Acceptance: overlay entries are listable, attributable to their promoting run, and removable; a run with overlay vs without is diffable in telemetry.
Part of the v0.9.0 EPIC.
Implement the cached-main overlay: promoted notes, workflows, tests, branch heuristics, model/cache policies, and prompt patches warm future runs without mutating Git main.
Acceptance: overlay entries are listable, attributable to their promoting run, and removable; a run with overlay vs without is diffable in telemetry.
Part of the v0.9.0 EPIC.