feat(app): add Status button popover to session header (per Figma request)

[kearns-cu]

Implementation follows Figma design request.

Fixes#10111

Summary

Adds a Status button to the session header that shows a popover with system status across four tabs: Servers, MCP, LSP, and Plugins.

• Status button appears after session starts (matches Share button behavior)
• Aggregate health indicator shows green/red/gray based on connectivity
• Servers tab shows health, version, default indicator, and active checkmark
• MCP tab shows connection status with toggles to connect/disconnect
• LSP tab shows language server status
• Plugins tab shows installed plugins
• Full i18n support

Video

NOW.feat.status-popover.mov

Changes

• Feature: Added StatusPopover component and integrated it into SessionHeader
• UI: Fixed Switch component styling (prevented white background on hover for checked state, fixed cursor for disabled state)

Verification

Tested in the web app:

• Opening a project and starting a session
• Clicking the Status button to verify popover opens
• Switching between all four tabs
• Verifying server health indicators update (refreshes every 10s when open)
• Toggling MCP servers on/off
• Scrolling behavior in lists with many items

[kearns-cu]

@adamdotdevin Only addition I made beyond the figma design was adding a max height and scroll bar to keep the size of the card consistent across the tabs. Please advise on the scroll bar if you prefer it changed.

[ilovebamboo]

I also use Fima for frontend design, but it's a bit more complex when integrating with other AI tools in practice, especially when there's a separation between the front and back ends. As for the architecture, the code written by AI isn't very good, with various bugs. Although our frontend is already done, with documentation and guidelines, it still has all sorts of issues. It's like if you don't have programming experience, their integration still has some flaws, many flaws.