Priority: Medium\n\nWhen a plan is amended mid-year (rate change, accelerator adjustment), the system should create a new plan version with an effective date rather than overwriting the existing plan. Historical calculations must reference the plan version that was active at the time of each transaction. Add a version history panel to the plan editor.
Priority: Medium\n\nWhen a plan is amended mid-year (rate change, accelerator adjustment), the system should create a new plan version with an effective date rather than overwriting the existing plan. Historical calculations must reference the plan version that was active at the time of each transaction. Add a version history panel to the plan editor.