Fix: Cleanup of example apps and tutorial, added axis labels.

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---

name: Pull Request
about: Create a pull request to contribute to the project
title: 'Fix: Add missing plotly axis labels and clean example apps'
labels: 'bug'
assignees: ''

Related Issue
Fixes #656

Description of Changes

• Updated Travel, Earthquake, and Tutorial example apps to add missing x-axis and y-axis labels to Plotly visualizations.
• Improved readability by cleaning and consolidating example app code.
• Removed redundant comments and aligned style for consistency.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• Code cleanup and documentation improvements

Tests Performed

• Verified that the Travel dashboard now shows "Accommodation Cost (USD)" on x-axis and "Number of Trips" on y-axis.
• Verified that the Tutorial app's Selectbox histogram now displays the selected column name correctly on x-axis and "Count" on y-axis.
• Verified that Earthquake dashboard histograms have correct axis labels.
• Manually tested rendering in Preswald app preview.
• Confirmed no errors, regressions, or warnings.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented important sections where needed
• My changes generate no new warnings
• I have tested the app examples manually and ensured no errors

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Thanks for maintaining Preswald! Truly enjoyed contributing to the mission — excited to help more in the future!