1. Extract parseTokenKey helper function to eliminate code duplication
2. Add channelId validation to prevent invalid formats like sk-abc:def:ghi
3. Add database migration to drop deprecated bound_channel_id column
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add the new pricing models to both migrateDB() and migrateDBFast()
functions to enable automatic table creation on database initialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>