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/fetch_missing_actors.py

@@ -106,7 +106,8 @@ def fetch(missing_path, out_path, token, build_dir, models_dir, arcface,
                   f"(wiki={n_via_wikidata}) no_tmdb={n_no_tmdb} no_img={n_no_img} "
                   f"no_face={n_no_face}", file=sys.stderr)
 
-    # TRACES: GR-004 | SR-001 — the legacy JSON gallery carries the same stamp as
+    # TRACES: GR-004 | SR-001
+    # the legacy JSON gallery carries the same stamp as
     # the HDF5 one; src/gallery/gallery_store.cpp reads it from either.
     Path(out_path).write_text(json.dumps({"embedder": stamp, "actors": actors}, indent=2))
     n_emb = sum(len(a["embeddings"]) for a in actors)
@@ -120,7 +121,8 @@ def fetch(missing_path, out_path, token, build_dir, models_dir, arcface,
 def merge(base_path, add_path, out_path):
     base = json.loads(Path(base_path).read_text())
     add = json.loads(Path(add_path).read_text())
-    # TRACES: GR-004 | SR-001 — merging two galleries from different models makes
+    # TRACES: GR-004 | SR-001
+    # merging two galleries from different models makes
     # ONE file containing two incompatible embedding spaces. Nothing downstream can
     # ever untangle that, so this is the one place the check must run before, not
     # after, the write.