◇ Could this help me?
Yes, and the design choice is the part worth copying. Accumulated customization is a genuine and nearly invisible cost, because stale skills and memory files are loaded on every conversation and the damage shows up as odd, confidently wrong context rather than as an obvious error. The important detail is that this routine reports and asks rather than deleting on its own, which is exactly right: an automated cleaner that removes configuration will eventually remove something load-bearing, and the recovery cost is far higher than the token saving. General practice, and the honest caveat is that an audit is only useful if it runs regularly, since a one-time prune leaves the same accumulation to rebuild.
Build me an audit routine for everything that loads automatically when a conversation starts. Inventory my project instructions file, my memory files, and every installed skill, and for each item report when it was last plausibly relevant, roughly how much context it costs on every conversation, and whether anything else in the set overlaps or contradicts it. Group the results into keep, compact, and candidate for removal, with your reasoning for each. Do not delete, move, or edit anything on your own: produce the review and wait for me to decide. Then tell me how often this is worth re-running for a setup that changes as much as mine does.