Adds Tunecaster Rock Top 30 for 1996-01-13, 1996-04-13, 1996-07-13, and
1996-12-14, cross-checked against all 4 existing 1995 shows and each other
for exact-track duplicates.
Also fixes a real false-positive: "John Mellencamp - Just Another Day" was
matching Jon Secada's unrelated song of the same generic title, because a
perfect title score could carry a middling-but-not-absurd artist-name
coincidence (0.56) over the acceptance threshold. Added a hard artist
similarity floor (0.65) independent of the combined score.
Claude-Session: https://claude.ai/code/session_01L7Rwa6guD5wK8F8tWQwcJX
