fix: pinned context styling fixes

[avi-alpert]

Problem

The prompt top bar component had several issues that needed to be addressed:

1. Context pills border colors were too bold
2. Font size in the top bar buttons was too large
3. Calculation error in the responsive layout logic that incorrectly handled available space: The width of the overflow pill was being double counted, so sometimes context pills wouldn't be visible even if there was enough space
4. Inconsistent test IDs with typos (tobBar instead of topBar)

Solution

This PR implements several improvements to the prompt top bar component:

UI Improvements

• Added proper border color to context pills, set font size for top bar buttons
• Fixed overflowWidth being double counted in the responsive layout calculation

Configuration Updates

• Enabled pinned context by default in the example app by setting showPinnedContext to true

Test Updates

• Updated UI test snapshots to reflect the visual changes
• Fixed test selectors to use the corrected test IDs
• Fixed typos in test IDs by renaming all instances of tobBar to topBar

These changes improve the visual consistency and functionality of the prompt top bar component while ensuring tests pass correctly.

Screenshots:
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After:

Before:

After:

Tests

• I have tested this change on VSCode
• I have tested this change on JetBrains
• I have added/updated the documentation (if applicable)

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.