Invoice Retainer Applications Table Structure:
id - int(11) - NO - 
invoice_id - int(11) - NO - 
retainer_amount_applied - decimal(10,2) - NO - 
retainer_balance_before - decimal(10,2) - NO - 
retainer_balance_after - decimal(10,2) - NO - 
created_at - timestamp - NO - current_timestamp()

Retainer Balance Snapshots Table Structure:
id - int(11) - NO - 
client_id - int(11) - NO - 
balance - decimal(10,2) - NO - 
as_of_date - date - NO - 
created_at - timestamp - NO - current_timestamp()

Sample Invoice Retainer Applications:
Invoice ID: 567
Client: Ronald Dal Bello
Amount Applied: 2700.00
Balance Before: 2700.00
Balance After: 0.00
-------------------
Invoice ID: 568
Client: Ran Liu
Amount Applied: 2900.00
Balance Before: 10000.00
Balance After: 7100.00
-------------------
Invoice ID: 565
Client: Erica Ehrenberg
Amount Applied: 8250.00
Balance Before: -15850.00
Balance After: -24100.00
-------------------
Invoice ID: 565
Client: Erica Ehrenberg
Amount Applied: 8250.00
Balance Before: 650.00
Balance After: -7600.00
-------------------
Invoice ID: 569
Client: Ran Liu
Amount Applied: 2400.00
Balance Before: 7100.00
Balance After: 4700.00
-------------------

Sample Retainer Balance Snapshots:
Client: Barry Waldman
Balance: 4000.00
As of Date: 2025-05-16
-------------------
Client: Ronald Dal Bello
Balance: -2700.00
As of Date: 2025-06-05
-------------------
Client: Ronald Dal Bello
Balance: 0.00
As of Date: 2025-06-05
-------------------
Client: Ronald Dal Bello
Balance: 2700.00
As of Date: 2025-06-05
-------------------
Client: Anthony Rohm
Balance: 5000.00
As of Date: 2024-12-10
-------------------