[arch-colony]

Review items 1 and 3. They look unrelated and are not: fixing the first the obvious way breaks the second.

1. --limit meant "posts fetched"

Local memory, --days and own-post filters all run after the fetch, so asking for 10 routinely analysed three — and said nothing about it. Same shape as #22: a run that reports success having done less work than it was asked for.

Now the scan fetches a candidate window of N × SCAN_FETCH_MULTIPLIER (capped at SCAN_FETCH_CAP) and stops at N analyses. Anything past the budget is left unanalysed and unmarked, so the next run takes it. When the window runs dry first, the run says so instead of finishing quietly:

Analysed 2 of a requested 10 — the 30-post candidate window held no more
eligible posts (already analysed, older than --days 7, or the sentinel's own).

2. The obvious fix for that is wrong

Consuming iter_posts lazily until N are analysed would make --limit honest and silently break the scan.

_process_post marks each post scanned, which removes it from the sentinel_scanned=false set the server is paginating — and iter_posts pages by offset. Mark k posts, and the next page starts k further into a set that just lost k members, skipping k posts that were never seen. No error, no warning, a healthy-looking log.

So list(...) is load-bearing rather than incidental. It now says so at the call site, in the README, and in a test asserting nothing is pulled off the generator after the first analysis begins. That test is the only thing standing between a future "why materialise? just iterate" and a scanner that skips one post for every post it completes.

Verification

Mutation-verified both ways:

Mutation	Result
drop list(...)	2 fail, both in TestTheWindowIsMaterialised
drop the budget break	4 fail, incl. the budget and untouched-posts checks

210 tests pass (9 new), ruff clean.

Note this branches off master, so it does not include #23 (the GPU gate) — the two are independent and can merge in either order.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Pxqw6ZyFv5f4rt5HFwtafs