docs(web): Better Transparency for OpenCode Go Documentation

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Hi, I love the app in general, love what you're doing but I feel like there could be some better transparency in the documentation with some things.

Usage Limits

• I only found out recently some models only have a $15 per month usage limit and this is buried in the documentation. It would have been best to add a side note right at the top of https://opencode.ai/docs/go/#usage-limits so it's not hidden.
• When I view my GO sub usage limits at https://opencode.ai/workspace/<WORK_SPACE_ID/go It shows the usage left based on the $15 per month model usage, not what I still have left for $60, which is confusing. You might want to show different charts for the different usage limits.

Model Training from Data

• I only use paid models because I assume they don't train on my data. I had to Google Muse Spark 1.2 Contributor to find out that it trains on data. I think any paid model that trains on data should be clearly annotate

Start with the Go documentation page at opencode.ai/docs/go/#usage-limits and the workspace Go usage page at opencode.ai/workspace/<WORK_SPACE_ID>/go. Review how the $15 and $60 limits and model data-training policies are currently presented. Done means the limits and training disclosures are clearly visible and the different usage limits are distinguishable.