Deep-review round 2, on round 1's own fix commit. It found MORE than round 1
did (28 raw, against 13), and most of it was mine -- a new piece of UI attracts
findings a backend-only diff never does. The pattern in almost all of them is
the same: a principle applied to the site that prompted it and not to its
siblings.
* `display_text` reached three of the FIVE writers of a user-supplied name.
`POST /api/downloads` and `POST /api/downloads/edit` still handed Postgres an
unbounded string, so a 300-character name pasted into the Add-download dialog
or the editor was a bare 500 (main.py re-raises every DataError but the NUL
case). Four of the seven reviewers found it independently. The bound now lives
in `models.py`, the three columns are DECLARED with it, and the guard for the
next writer is parsed rather than remembered: every `display_name` /
`display_uploader` assignment under `app/routes/` must go through the helper.
That guard immediately found two more -- the Google sign-in callback writes
the profile name into the same 255-wide column -- so it is six, not five.
* The connection release reached one of the THREE routes that read their own
body. The screenshot route (10 MiB, from a phone) and the client log sink both
still held a pooled connection idle-in-transaction for the length of the
upload, which is the invariant db.py sizes the pool on. All three now call
`db.release_read_connection`, whose precondition -- nothing pending on the
shared session -- is CHECKED rather than described, because a whole-session
rollback discarding a caller's staged write is a mistake this repo has already
made once. `test_body_limit.py` holds the rule for the next such route.
* The AST drift registry keyed its sites by (module, limit expression), so a
second route copied from the first collapsed onto the same entry and went
uncovered -- the exact hole the registry exists to close. Keyed per call site
now, and it carries the release requirement too.
* The dialog's own refusal was announced once and never again: two over-cap
picks leave an identical node with identical text, and an untouched live
region says nothing. It is keyed per pick now, the drop zone reads as invalid
and points at the sentence, and the reason is reachable from the control
rather than only from a one-shot announcement.
* Two tests rebuilt the blind spot they were written to remove: the dialog's cap
test sat nowhere near the boundary (a `>` loosened to `>=` survived it, which
is the mutation round 1 fixed on the server side), and the header-precedence
test only covered an exact-case duplicate while a differently-cased one would
have been COMBINED onto the wire rather than replaced. Both fixed, and the
merge now dedupes case-insensitively because header names are.
Also: the upload dialog's unstubbed usage query was firing a real request from
jsdom in a neighbouring suite and leaking a delayed "connection lost" toast
across test boundaries; `GET /api/downloads/usage` had no test at all though the
whole client-side check hangs off it; and the comment claiming the edge 413 is
readable now says what was measured -- readable to 200 MiB over loopback, a bare
`onerror` through a proxy -- so the pre-send check is named as the mechanism and
that branch as the backstop it is.
Every test added or changed here was mutation-checked. One mutation SURVIVED and
is recorded rather than papered over: the `tooBig` term inside `submit()` cannot
be reached, because `ui/Button` swallows the activation itself, so it is marked
as belt and braces instead of being described as the guard.