Database connections kept open; a click's wait is measured (#241, #245, #246)

#241: on production, All Subscriptions' query runs in 31 ms, unread oldest-first in 30, the
feed list's count in 5, generic plans included (EXPLAIN ANALYZE, BUFFERS, read only), against
0.3-1.6 s in ipx. A new Postgres connection takes 80-330 ms to open, and a page load asks for
more than are idle: four of six slow loads came as the pool grew (3 to 6, 2 to 6, 3 to 5, 6 to
8), and 20 requests at once took a median 414 ms while the pool grew from 8 to 20. The daemon
and the directory's server now keep their whole pool open (min = max); a command such as `ipx
status`, and the tests, which share the server's 100 connections, open as they need.

#246: the page reports list_shown, the ms from asking for a list to drawing it, with the view
and filter, under the click's trace; background refreshes are not timed. Timings skip report()'s
once-a-minute limit, which is for errors in a loop. A dashboard panel and table, and the prod
check, read it.

#245: the load test's browse scenario subscribes by OPML and leaves the Directory, which is
ipx-directory's since #204, to it.

CLAUDE.md records the owner's leave to EXPLAIN (ANALYZE, BUFFERS) any query on production,
read only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ipx/CHANGELOG.md

@@ -16,6 +16,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - A feed that sends the same body again, as Patreon and Substack do whatever they are asked, is taken as unchanged instead of read again, and, without a schedule of its own, checked less often the longer it stays the same, up to every four hours, back on schedule when it changes (#242).
 - Feeds are fetched accepting brotli and zstd as well as gzip (#244).
+- On Postgres the daemon keeps all twenty of its database connections open, so a page load no longer waits for new ones, 80-330 ms each: the feed list and item lists took 0.3-1.6 s now and then, where their queries take 5-30 ms (#241).
+
+### Added
+
+- The page's report of how long a list took to show after a click (`list_shown`, with the view and filter) is logged under that click's trace (#246).
 
 ## [1.2.0] - 2026-10-15