Fix contrast issues in the agentic UI

[katinthehatsite]

Related issues

Related to STU-1970

How AI was used in this PR

It was used to audit the contrast issues and raise contrast on problematic items.

Proposed Changes

This PR ensures that we don't have the contrast issues for accessibility reasons in the agentic UI. It fixes the contast on the time displayed in the sidebar for the sessions as well as the low contrast on the site form descriptions:

Before

After

For now, they were no other contrast issues flagged.

Testing Instructions

• Visually review the changes and confirm they look good

Alternatively:

• Install axe tools with npm install --save-dev @axe-core/react --workspace=apps/ui
• Add this code to apps/ui/src/main.tsx:

  import React from 'react';                                                                                                          
  import ReactDOM from 'react-dom';                                                                                                   
                                                                                                                                      
  if ( import.meta.env.DEV ) {                              
      void import( '@axe-core/react' ).then( ( axe ) => {                                                                             
          void axe.default( React, ReactDOM, 1000 );                                                                                  
      } );
  } 

• Start Studio with npm start
• Enable the Agentic UI feature flag from Studio -> Feature flags from the topbar
• Click on the New site -> Create new option
• Open the dev tools
• Run this bit in the console:

axe.run().then(results => console.table(results.violations.flatMap(v =>
v.nodes.map(n => ({ rule: v.id, impact: v.impact, element: n.html, message:
n.failureSummary })))))   

• Confirm there are no issues regarding the contrast in the site form in the console
• Close the add site form and start a chat
• Confirm that there are no contrast issues related to the duration of the chat session in the console

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[katinthehatsite]

I tried to avoid using !important but was not able to get around it to solve the contrast issues. Open to suggestions if anyone has alternatives to offer

[wpmobilebot]

📊 Performance Test Results

Comparing 3043877 vs trunk

app-size

Metric	trunk	3043877	Diff	Change
App Size (Mac)	1350.65 MB	1350.64 MB	0.01 MB	⚪ 0.0%

site-editor

Metric	trunk	3043877	Diff	Change
load	1034 ms	1087 ms	+53 ms	🔴 5.1%

site-startup

Metric	trunk	3043877	Diff	Change
siteCreation	6997 ms	7022 ms	+25 ms	⚪ 0.0%
siteStartup	2402 ms	2381 ms	21 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[bcotrim]

LGTM 👍