Revamp AdminLTE UI and improve endpoint editor usability

[javaChip56]

Summary

This PR refreshes the local dashboard/editor UI around the offline AdminLTE assets already in the project and improves the endpoint editing workflow in the cURL editor.

What Changed

• revamped the dashboard and cURL editor to use AdminLTE-native cards, buttons, badges, forms, and layout patterns
• updated dynamic frontend rendering so selection trees, result cards, YAML previews, and editor rows match the AdminLTE look and feel
• increased the default height of the cURL and response-body textareas for easier editing
• left-aligned added assertion rows for better readability
• fixed endpoint editing so URL-encoded route placeholders like %7BcustomerId%7D are saved back as {customerId}
• fixed edit-endpoint loading so endpoint names populate correctly for endpoint-only YAML files using targetEnvironments
• added assertion edit cancel support
• added inline assertion editing with row-level Edit, Save, and Cancel

Why

These changes make the UI more consistent and easier to use, while also fixing a few editor-specific issues that made endpoint maintenance harder:

• encoded paths were being written back into YAML
• some endpoint names were not loading into the editor
• assertions were harder to manage without inline editing/cancel support
• code-oriented textareas were too small for practical editing

Validation

• ran dotnet test tests\ApiTestRunner.App.Tests\ApiTestRunner.App.Tests.csproj
• all app tests passed

Notes

This PR focuses on the local web UI and editor workflow only. Backend test execution behavior is unchanged except for the path decoding fix in the editor/analyzer flow.

[javaChip56]

Looks ok.