[FEATURE] Suggest a Nerd Font during onboarding for Windows users — default Consolas tofus the TUI indicator glyphs

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Summary

On a fresh Windows 11 install, opening a PowerShell window uses the legacy
console host (conhost.exe) with the default font Consolas. Consolas is
missing glyphs for several codepoints that Claude Code's TUI emits — notably
the mode-indicator icons next to status rows like auto mode on, and a
handful of hyphen / NBSP variants (U+2011, U+2010, U+2012, U+2212, U+00A0)
that appear in pasted prose and identifiers.

The result: a new Windows user sees tofu boxes (□) in the TUI and broken
glyphs in their own text, with no in-product guidance on how to fix it.

## Environment

• Windows 11 Pro 26200
• PowerShell 7+ (pwsh.exe) launched in legacy conhost (NOT Windows Terminal)
• Default console font: Consolas
• Claude Code v2.1.150
• Codepage: 65001 (UTF-8) via chcp 65001 — encoding is fine, this is purely

a font glyph-coverage issue

## What I see

• Tofu (□□) immediately preceding the auto mode on indicator row
• The ⎿ tool-result connector renders inconsistently across some installs
• U+2011 / U+00A0 in user prose come through as broken-glyph boxes

## Root cause (confirmed)

Not an encoding bug. Switching the console font to Cascadia Code NF
(Microsoft variant, free, SIL OFL, downloadable from
https://github.com/microsoft/cascadia-code/releases) resolves every Claude
Code TUI glyph cleanly. The hyphen / NBSP set also renders correctly under
Cascadia Code NF. Note: Microsoft's NF variant does NOT include the broader
Nerd Font icon library — but for Claude Code itself, that subset is enough.

Proposed Solution

Suggestion

Add a one-time onboarding hint to Claude Code's first-run experience on
Windows when the active console font is detected to be Consolas (or any font
lacking key glyphs Claude Code emits). For example:

> "Your terminal font (Consolas) is missing glyphs Claude Code uses for its
> TUI. To fix this, install Cascadia Code NF
> (https://github.com/microsoft/cascadia-code/releases) and select it in your
> console Properties → Font tab. This is a one-time setup."

Even a single line in the Windows install docs or in the npm install
post-install message would save users a few minutes of confusion about why
their TUI looks broken when codepages and encodings are correctly set.

Alternative Solutions

_No response_

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_