Add bulk import optimization: track_lookup cache, batch inserts, BulkSubmitter

db/migrations/000006_track_lookup.sql

@@ -0,0 +1,15 @@
+-- +goose Up
+CREATE TABLE track_lookup (
+    lookup_key TEXT NOT NULL PRIMARY KEY,
+    artist_id INT NOT NULL REFERENCES artists(id) ON DELETE CASCADE,
+    album_id INT NOT NULL REFERENCES releases(id) ON DELETE CASCADE,
+    track_id INT NOT NULL REFERENCES tracks(id) ON DELETE CASCADE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_track_lookup_track_id ON track_lookup(track_id);
+CREATE INDEX idx_track_lookup_artist_id ON track_lookup(artist_id);
+CREATE INDEX idx_track_lookup_album_id ON track_lookup(album_id);
+
+-- +goose Down
+DROP TABLE IF EXISTS track_lookup;