[Feature]: Independent font size/family for the sidebar vs. the conversation text

[cornishandy]

Problem or use case

Today, Interface font size and Interface font (fontFamilySans) control the sidebar and the conversation text together. Prompt already has its own size and font, which works really well. But when I raise the interface size until the session/conversation text is comfortable to read (even with zoom), the sidebar grows just as much. Thread titles get cut off and the panel takes up too much room.

What I want is:

• Sidebar and app chrome: medium to medium-large text in a condensed/narrow font, so thread and project names still fit.
• Prompt input: much larger (this is already possible, thanks!).
• Session/conversation text (user and assistant messages, the context of the session): much larger too, without making the sidebar bigger.

Proposed solution

In Settings → Appearance / Typography, split the current Interface setting into separate settings for:

1. Sidebar / chrome: its own font size and font family (e.g. a condensed family). This could be the default "app text" setting that the rest of the UI chrome uses.
2. Conversation / transcript: its own font size (and ideally font family) for message prose and rendered Markdown, covering both user and assistant messages.

Keep the existing Prompt, Code, and Terminal settings as they are. Each new control should work like the current ones: live preview, reset to default, and persisted.

Alternatives considered

• Whole-app zoom or a larger interface font size: this scales the sidebar too, which is exactly the problem.
• Picking a condensed interface font: this also condenses the conversation text, which I want large and easy to read, not narrow.

Related

• Discussion [Feature]: Independently configurable font size for AI responses #10769 (independent AI-response font size) is a subset of this request. This one adds independent sidebar sizing and font family, and covers the whole conversation, not only assistant replies.
• [Bug]: Files tree ignores Interface font size and remains fixed at 12px #7957 (the Files tree ignores Interface font size) is related because it's about per-surface sizing.