Simplify chart legend labels

[braddf]

• Remove OCF from single source model names in UI.
• Remove Estimate from PV Live Initial Estimate.
• Change latest to current
• Remove OCF from OCF’s latest and 4hr forecast.

[revaarathore11]

@braddf @dfulu please assign me this issue.
To simplify the chart legend labels, I would:
1. Locate all legend label definitions in the UI code (either in a constants file or the chart/tooltip components).
2. Update the text strings according to the requested changes:
• Remove “OCF” from single-source model names
• Remove “Estimate” from “PV Live Initial Estimate”
• Change “latest” to “current”
• Remove “OCF” from OCF latest and 4-hour forecast labels
3. Ensure consistency by updating the same labels in any tooltips, datasets, or legends that reuse these strings.
4. Run the UI locally to verify that:
• The updated labels appear correctly
• The legend layout still looks clean
• No visual or functional issues were introduced