repro: asked for one error string, got 9 files back (agent mode, on 0.51)

ok. 0.51, agent mode. repo is our scheduling app, about 30k lines, and i wrote most of it so its not some legacy horror where nobody knows what anything does. the ask was change the copy of one error string in `apps/web/lib/sched.ts:214`. one line. what came back: - the string changed, correct, fine - two test files reformatted end to end, every line, prettier config i assume - a helper renamed from `fmtSlot` to `formatSlot` in 4 places - a try/catch wrapped round `apps/web/app/api/slots/route.ts` that it decided the route needed - a jsdoc comment deleted off something unrelated, i assume because it decided the code was self documenting 9 files. i asked for 1. i have a rules file. it says in plain english do not modify files you were not asked to modify. i have reworded that line probably nine times now including once in caps and it does not `care`. the caps one was worse if anything, i don't know what that tells you. things that did not work: telling it to make minimal changes (that reads as `vibes`, does nothing), telling it the diff must be under 20 lines (it splits the work over two turns and hands you 40), asking it to explain before editing (it explains beautifully and then edits everything anyway). what i want is the wording. not the theory of why agents do this, i dont care why. the prompt. ideally one that survives a build on 0.48 this was `better` and i have no proof of that whatsoever and i know exactly how that sounds