fix: ReccoBeats audio features and OpenAI narrative generation

- Add reccobeats_id column to Track model for API mapping
- Fix ReccoBeats batch size limit (max 40 IDs per request)
- Extract spotify_id from href field in ReccoBeats responses
- Fix OpenAI API: remove unsupported temperature param, increase max_completion_tokens to 4000
- Add playlist/user management methods to spotify_client for future auto-playlist feature

backend/alembic/versions/b2c3d4e5f6g7_add_reccobeats_id.py

@@ -0,0 +1,25 @@
+"""Add reccobeats_id column to tracks table
+
+Revision ID: b2c3d4e5f6g7
+Revises: a1b2c3d4e5f6
+Create Date: 2025-12-30
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "b2c3d4e5f6g7"
+down_revision = "a1b2c3d4e5f6"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("tracks", sa.Column("reccobeats_id", sa.String(), nullable=True))
+    op.create_index("ix_tracks_reccobeats_id", "tracks", ["reccobeats_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_tracks_reccobeats_id", "tracks")
+    op.drop_column("tracks", "reccobeats_id")