Fix visual inconsistency between changes file count and customization counts

[Copilot]

The file count badge in the Changes panel header used a pill/badge style (background, border-radius, bold weight) while customization counts in the sidebar used plain dimmed text — two different treatments for semantically equivalent summary numbers.

Removes the badge styling from .changes-files-count to match the .source-count-num style used by customization counts:

/* Before */
.changes-view-body .changes-files-count {
    padding: 2px 0;
    border-radius: 4px;
    background-color: color-mix(in srgb, var(--vscode-foreground) 10%, transparent);
    font-weight: 600;
    min-width: 16px;
    text-align: center;
}

/* After */
.changes-view-body .changes-files-count {
    color: var(--vscode-descriptionForeground);
    opacity: 0.8;
}

Original prompt

Fix issue #307707

Created from VS Code.

[Copilot]

Pull request overview

Aligns the “Changes” panel file-count styling with the “Customizations” sidebar count styling in the Sessions (Agents) window, resolving the UI inconsistency reported in #307707.

Changes:

• Removes pill/badge-like styling (padding, background, border radius, bold weight, fixed min-width) from .changes-files-count.
• Applies the same subdued count treatment used by customizations (--vscode-descriptionForeground with opacity: 0.8).

Show a summary per file

File	Description
src/vs/sessions/contrib/changes/browser/media/changesView.css	Simplifies .changes-files-count styling to match the customizations count visual treatment.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0