chore: re-bless ui/gallery.ts Linux baseline + sync Cargo.lock

The Linux gallery baseline was a stale 900x1024 capture from before
the example header settled on 900x1400 — the doc-tests harness
flagged it as "size mismatch: actual 900x1400 vs baseline 900x1024"
on every Linux run since (documented in CLAUDE.md v0.5.304 as the
"retina baseline mismatch"). Re-blessed via `doc-tests --bless --filter
ui/gallery` on Fedora 43 / GTK 4.20.4. Full ui/ harness on Linux now
44/45 pass, 0 fail, 1 skip (image_symbol banner excludes Linux —
unrelated). macOS (970) and Windows (788) baselines are likewise stale
relative to the 1400px header but those need re-bless from their
respective hosts.

Cargo.lock sync: workspace bump to 0.5.324 in 8190ec6 updated
Cargo.toml's `[workspace.package]` version but didn't regenerate
the lockfile; first local build picked up the diff.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Ralph Kuepper