[Feature]: Detect Brave Origin as a cookie import source on Linux

[ruben-salas20]

Problem
On Linux, Settings → Integrations → Browser profiles → Add profile shows "No supported browser found" when Brave Origin is the only Brave installed. Brave Origin (brave-origin-bin 1.97.59 on Arch) keeps its user data in ~/.config/BraveSoftware/Brave-Origin, with cookies in Default/Cookies. T3 Code only looks in ~/.config/BraveSoftware/Brave-Browser (apps/desktop/src/preview/BrowserImport/Sources.ts, Brave entry). On this machine that folder only contains NativeMessagingHosts, so Brave is reported as missing.

Proposal
Add Brave Origin as a separate Chromium source (or as an extra path for the Brave entry) on Linux, pointing to BraveSoftware/Brave-Origin. I have not checked which libsecret application name Brave Origin uses for its Safe Storage key, so that part may need confirming.

Environment
T3 Code desktop 0.1.0, Arch Linux (Omarchy, Hyprland).

Drafted with Claude Code (Claude Opus 5.5).