chore(traces): put TRACES tags on their own line; regenerate the report

The parser reads a tag up to end of line, so `# TRACES: GR-004 | SR-001 —
prose` swallowed the prose into the tag and the row went unmatched. Splitting
the comment leaves the tag greppable by the same pattern as the code tags and
the commit trailers, which is the point of the house format.

Mechanical throughout; no logic touched. The regenerated report reflects this
session's new tags: 137 -> 148 found, and one more tagged-but-unexecuted, which
is the SuperHero accuracy assertion that is documented but not yet a test.

scripts/optimizer/reembed_gallery.py

@@ -59,7 +59,8 @@ def main():
     ref = load_gallery_hdf5(Path(args.ref))
     images_root = Path(args.images)
     embedder = load_embedder(args.build_dir, args.models_dir, args.arcface)
-    # TRACES: GR-004 | SR-001 — this script exists to produce a gallery in a
+    # TRACES: GR-004 | SR-001
+    # this script exists to produce a gallery in a
     # DIFFERENT model's space from the reference. The output must therefore never
     # inherit the reference's stamp; it carries the stamp of --arcface, which is
     # the whole point of the bake-off being safe to run.