[httpsphl]

A new look for the app, in four commits. The first PR of a stack of six: each one after it builds on this one.

What changes

• Avatars without the black square. A bot is now just the mascot in its color, with a thin edge (dark on the light theme, light on the dark one) so light colors keep their shape. Botloft's own white mascot keeps the black square of the app icon, since it would vanish on the light theme without it.
• A bigger app, with a size setting. The whole window is drawn at 125% by default (the webview's zoom), so text, spacing, icons and avatars grow together; at 100% the app looked tiny on a monitor without Windows scaling. 100%, 110%, 125% and 150% are available, Ctrl+= and Ctrl+- step through them and Ctrl+0 goes back to the default. The choice is applied before the first paint, so the window never flashes small.
• An account area at the bottom of the sidebar, like a chat app: the owner's Windows name, their Claude plan and a menu with Usage, Settings, Language, What's new and Help. Usage shows each window of the plan and when it resets; Settings holds the theme, size, language and versions. Theme, size and language leave the title bar, which keeps only the language on the setup screens. The daemon reads the display name once (GetUserNameExW) and the email, plan and organization from claude auth status, and sends them in system.status.account.
• Rounder and softer. 8 px corners on buttons, fields and menu rows, 12 px on cards and menus, 16 px on the chat's bubbles, cards and dialogs. Menus and dialogs float on a light shadow that is stronger on the dark theme. The chat is a centered column with the day as a pill, and the open conversation in the sidebar is an inset rounded block. Menus share one popover look and one hook that closes them.

Spec: 15.1 (account area) and 15.3 (size, corners, shadow, identity).

Tested

• cargo fmt, clippy -D warnings and cargo test pass; pnpm check passes.
• Browser preview in the dark and light themes: avatars on both, the four sizes and the shortcuts, the account menu and its dialogs, and the new corners across the sidebar, chat, dialogs and menus.

To check in the installed app

• The account area shows the Windows display name and the Claude plan of the signed-in account.