[FEATURE] Add setting to right-align user messages in chat UI

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

In the Claude Code VS Code extension, user messages and Claude's responses
are both left-aligned and use very similar styling. In longer conversations
this makes it hard to tell at a glance whose turn it is — I have to actually
read each message to figure out who said what when scrolling back to find an
earlier prompt or re-read my own reasoning during a multi-step session.

Every other chat tool I use daily (iMessage, WhatsApp, Slack DMs, Messenger,
ChatGPT, Claude.ai web) lets me distinguish messages from peripheral vision
alone, so the current layout breaks muscle memory and adds cumulative friction
to longer coding sessions where the chat panel is the primary interface.

I checked the related issues before opening this one:

• #28264 (Improve visual distinction of user messages in VSCode chat panel)

— closed as duplicate, no comments, no pointer to where the discussion
continues.

• #20656 (Customize user input message colors) — also closed as duplicate,

no resolution visible.

• #25517 (RTL support for VS Code extension chat panel) — closed as

duplicate; different problem (right-to-left languages).

• #42685 (Change the color of my text) — open, but no comments and no

official response. Focused on the terminal UI rather than the VS Code
extension, and proposes color changes rather than layout changes.

Three of the four were closed as duplicates without visible discussion, and
the open one has had no engagement either. The underlying problem has been
raised repeatedly over many months and remains unaddressed. None of these
issues specifically propose right-alignment — they all focus on color or
styling tweaks, which is a structurally different approach from layout, so
this request shouldn't be folded into one of those existing threads.

Proposed Solution

Add a setting to the Claude Code VS Code extension that, when enabled,
right-aligns user messages while keeping Claude's responses left-aligned —
matching the convention used by iMessage, WhatsApp, Slack DMs, ChatGPT,
Claude.ai web, and most other chat UIs.

Concretely:

1. A new boolean setting (e.g. claudeCode.chat.alignUserMessagesRight),

accessible through the standard VS Code Settings UI and searchable as
"Claude align user messages".

1. Defaults to false so existing users see no change unless they opt in.

1. When enabled, user messages render flush to the right edge of the chat

panel; Claude's responses continue rendering flush to the left. Same
fonts, same colors, same widths — only horizontal alignment changes.

1. Applies immediately without reloading the extension, and persists at

User settings scope (it's a personal readability preference, not a
per-workspace one).

A single toggle, no new commands, no theming system. Just an alignment
switch that lets users opt into the chat-app convention.

Alternative Solutions

I didn't seriously consider alternatives. Right-alignment is the convention
used by virtually every modern chat UI, so it felt like the natural fit
rather than something to weigh against other options. Other approaches
(colored bubbles, accent bars, prefix markers) have been proposed in related
issues and could be added later if needed — they don't conflict with
alignment.

Priority

Medium - Would be very helpful

Feature Category

Other

Use Case Example

A typical scenario for me: I'm working through a multi-step debugging session
with Claude on a tricky bug — maybe 15-20 back-and-forth exchanges over an
hour. Halfway through, I want to scroll back to remind myself exactly how I
phrased my original question, because Claude's latest response is going in a
direction that doesn't quite match my actual goal.

Right now I have to scroll up slowly and read each message to figure out
which ones are mine, because everything is left-aligned with the same
styling. With right-aligned user messages, I could scroll past dozens of
exchanges and instantly spot my own messages by their position alone — the
same way I'd find my own messages in any chat app.

This isn't a hypothetical: it happens in almost every long session, and the
cumulative friction over a workday is real.

Additional Context

_No response_