fix(chat): improve light-theme contrast for agent-session-details-row

[naamyuvraj]

Associated Issue

Low contrast for secondary text in Chat view (light theme).

Description of Changes

This PR improves the light theme contrast for the chat agent metadata row (.agent-session-details-row) in the Chat panel.

Previously, it used --vscode-descriptionForeground, which appears too light on white backgrounds (~3.9:1 contrast ratio), making secondary info hard to read.

Now it uses:

color: var(--vscode-foreground);
opacity: 0.82;

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@bpasero

Matched files:

• src/vs/workbench/contrib/chat/browser/agentSessions/media/agentsessionsviewer.css

[bpasero]

I would prefer to stay with our semantic colors. Shouldn't the fix apply to the color itself?

vscode/src/vs/platform/theme/common/colors/baseColors.ts

Lines 25 to 28 in bb450f4

	export const descriptionForeground = registerColor('descriptionForeground',
	{ light: '#717171', dark: transparent(foreground, 0.7), hcDark: transparent(foreground, 0.7), hcLight: transparent(foreground, 0.7) },
	nls.localize('descriptionForeground', "Foreground color for description text providing additional information, for example for a label."));