fix: warn when weather data belongs to a different location and clearer labels

[giancarloerra]

Summary

Show a warning on the Location card when the configured observer location differs from
the location of the currently downloaded weather data.

Motivation

After changing location in Settings and navigating back to the Weather Dashboard, the
displayed coordinates belong to the previous download — which is confusing. Instead of
a static "Location Downloaded" label, the card now detects the mismatch and prompts the
user to refresh.

Changes

• Fetch /api/location on dashboard mount to get the configured observer coordinates
• Compare configured location with weatherData.metadata (>0.01° threshold)
• When mismatched: amber border on the Location card, amber globe icon, and a small
  inline warning with a clickable "refresh" link
• When matching: card looks exactly as before (label reverted from "Location Downloaded"
  back to "Location")
• Import AlertTriangle icon from lucide-react

Testing

• npm run lint passes
• npm run typecheck passes
• npm test passes
• Verified manually in dev / built production mode

Breaking changes

• No breaking changes

Screenshots (if applicable)

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