UI Freeze when selecting certain policy parameters( BLS → Consumer Price Index options ) in Report Builder

Branch: feat/report-setup-reflow

Description

While using the Report Builder on the feat/report-setup-reflow branch, the UI freezes and becomes unresponsive when selecting Consumer Price Index (CPI) options under Bureau of Labor Statistics (BLS). The freeze lasts until the value editor screen finishes loading, during which time the user cannot interact with any part of the application.

The issue is more pronounced for certain options (notably CPI-U and CPI-W), which cause longer freezes before the screen finishes loading.

Steps to Reproduce

1. Checkout branch feat/report-setup-reflow
2. Navigate to Report Builder
3. Under Baseline/Reform Simulation -> Policy -> More Options
4. Choose Create New Policy -> Parameters
5. Navigate to Bureau of Labor Statistics (BLS) -> Consumer Price Index -> Choose any CPI option (e.g., CPI-U, CPI-W, etc.)

Expected Behavior

• Selecting a CPI option should transition smoothly to the value editor screen.
• The UI should remain responsive or display a loading indicator while data is being fetched or computed.

Actual Behavior

• UI freezes and becomes unresponsive after selecting a CPI option.
• User cannot interact with any part of the application until the value editor screen finishes loading.
• CPI-U and CPI-W cause noticeably longer freezes compared to other options.
• Even after the editor screen loads, a lag persists until the parameter selector window is closed.

Possible Causes

• The issue may be caused by expensive computations or synchronous data fetching on the main thread.
• Adding async handling, loading states, or deferring heavy computation may improve UX.

Check out feat/report-setup-reflow and reproduce the freeze through Report Builder > Baseline/Reform Simulation > Policy > More Options > Create New Policy > Parameters > BLS > Consumer Price Index. Start by profiling the CPI-U and CPI-W transition and the value editor loading path to identify work that blocks interaction. Done means CPI selections transition without freezing the UI and the parameter selector remains responsive while loading.