The logs stop repeating what metrics and their own fields say (#363)

iPX logged scan_done after every scan: 921 lines a day, a fifth of the
log, nearly all "scan complete, 1 feed(s)" since scans became one or two
feeds at a time (#114). ipx_jobs_total, ipx_feed_fetches_total and
ipx_last_scan_age_seconds hold all of it. It is routine now, at debug, so
the page's log view keeps it. The dashboard's "feeds checked" series and
the prod check's check 4 read the metrics instead.

ipx-directory wrote each line's span twice, as `span` and in `spans`, and
neither added anything: a request's span repeated its method, path and
status, refresh.feeds repeated `checked`, a feed span was empty.

ipx::http stays: it repeats Caddy's access line and the span, but holds
the route pattern and ipx's own time, which the dashboard groups by.

The prod check's `status` line was the healthcheck's every 30 s; since
#218 it is only `ipx status` run by hand, and the skill says so.

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

crates/directory/CHANGELOG.md

@@ -10,6 +10,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Its JSON log lines no longer carry their span, once on its own and again in a list, which said nothing the line's own fields did not (#363).
+
 ## [1.4.1] - 2026-10-24
 
 ### Fixed

crates/directory/src/main.rs

@@ -89,6 +89,9 @@ async fn serve(path: &Path) -> Result<()> {
             tracing_subscriber::fmt::layer()
                 .json()
                 .flatten_event(true)
+                // Each line's own fields say all its span did, and the list said it again (#363).
+                .with_current_span(false)
+                .with_span_list(false)
                 .with_writer(std::io::stderr)
                 .with_filter(filter())
         }))