#3112 extension push: 'Requested visibility' line prints to stdout without the logger prefix, twice per run

Problem

swamp extension push (seen on 20261006.205014.0-sha.e9c9416b, log mode, dry run and real push) prints a bare line with no timestamp, level or logger category:

2026-10-06T21:20:32.156Z [INF] extension·push: Extension: "[@swamp](/u/swamp)/ssh"@"2026.09.28.1"
Requested visibility: default (registry decides)
...
2026-10-06T21:20:32.230Z [INF] extension·push: Dry run complete for "[@swamp](/u/swamp)/ssh"@"2026.09.28.1"
Requested visibility: default (registry decides)

It appears twice: after the Extension line and after the Dry run complete line. Every other summary line goes through the extension·push logger.

Expected

The requested-visibility line is a normal extension·push log line (so --quiet, --log-level and log formatting apply to it), printed once in the summary.

Reproduce

Any extension: swamp extension push manifest.yaml --dry-run --yes. Also with --visibility private (then the line names private).

Found while capturing dry-run samples for the manual (Lab #3071).