Feature: Display warning when no price is available

# Description
When no price is available from 1inch, display a warning that it can be fetched. (Optional: Add a retry button to try again)

# Requirements
- [ ] Without network connection the 1inch prices should be cached or display a warning to indicate that the prices can't be fetched currently.

# Background
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Start by tracing where 1inch prices are fetched and how the app handles a missing network connection. Done means the no-price state visibly warns that prices cannot currently be fetched, with caching or a retry button only if supported by the existing flow; verify the behavior with the relevant price-fetching and UI tests.

Written by the indexing model from the issue text.