feat(seed): overhaul seed data with public-domain composers and cross-composer remix repos

- Remove all broken references to deleted models: Conversation, ConversationMessage, MessageAction, UsageLog (muse_db.models), NoteChange/Phrase/Variation (muse_models), NoteDict (json_types), budget_cents/budget_limit_cents on User, PHRASE_TYPES, TRACK_IDS_*, REGION_IDS_*, _make_note_dict(), _make_variation_section() - Remove dead seeding sections: 18 (variations/phrases/note-changes), 20 (usage logs), 22 (conversations/messages/actions) - Clean force-wipe table list: remove 7 non-existent tables

New batch-14 archive composers (all Public Domain): Beethoven (Moonlight Sonata, Piano Sonatas 32), Mozart (K.331 Theme & Variations), Debussy (Suite Bergamasque / Clair de Lune), Satie (Gymnopédies), Schubert (Impromptus Op.90) MIDI sources: Mutopia Project (CC), piano-midi.de (Bernd Krueger, CC)

New batch-15 cross-composer remix repos (showing Muse VCS power across eras): gabriel/well-tempered-rag — Bach counterpoint meets Joplin syncopation sofia/nocturne-variations — Chopin Nocturne No.20 merged with Satie Gymnopédie No.1 marcus/moonlight-jazz — Beethoven Moonlight Mvt.1 jazzified with tritone subs yuki/clair-de-lune-deconstructed — Debussy atomized into granular ambient textures aaliya/ragtime-afrobeat — Joplin Maple Leaf Rag meets West African 12/8 polyrhythm

Seed now creates: 18 users, 35 repos, 1081 commits, 525 issues, 140 PRs, 105 releases, 629 Muse objects, 329 Muse commits with full tag taxonomy