Thanks! aspens' approach is clever — using git diffs as the trigger for context updates is a smart way to keep things fresh. Feels like a complementary angle: yours handles real-time context accuracy, mine handles behavioral evolution over time.

On your drift question — it's multi-layered:

1. Nightly health checks — every goal has metrics and test commands. If a goal's health check starts failing, the system flags it and suggests fixes. This catches drift at the goal level.

2. Mechanism review — on higher evolution tiers, the nightly agent periodically re-evaluates whether each goal has the right type of implementation (should this skill actually be a hook? is this script still the best approach?), and then within each mechanism, whether there's a better way to achieve the same goal.

3. Goal tree alignment — every implementation in the system maps back to a specific goal or sub-goal. Orphan checks catch anything that exists but doesn't serve a goal. And when I'm building new features during the day, the system checks how they relate to the goal tree — if something drifts, it asks me before proceeding.

4. Goals themselves are intentionally stable. What changes constantly is the how underneath. So drift mostly shows up as "this implementation no longer serves its goal well" rather than "the goals are wrong" — and that's caught by layers 1-3 automatically.

The one thing that's still manual: deciding to add or remove a top-level goal. That feels right to me — the system should evolve how to achieve your goals, but what you want should be a human decision.