Built-in browser can't load new Microsoft Teams web app

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

Problem
The in-app browser (Claude Browser pane) can't open the new Microsoft Teams web app. Navigating to https://teams.microsoft.com (or /v2) dead-ends on the "Classic Teams is no longer available" page and bounces back instead of loading the app. Outlook web (outlook.cloud.microsoft) works fine in the same pane; Teams does not.

Likely cause
Teams for Web only supports Edge/Chrome/Firefox (latest 3 versions) and Safari (latest 2), and requires third-party cookies (per Microsoft Learn: "System requirements for the Teams client"). The embedded browser is apparently not recognized as a supported browser (non-standard user-agent / engine), so Teams refuses to load.

Request

• Present a supported Chromium user-agent (recent Chrome/Edge) for the in-app browser, and
• allow third-party cookies (at least opt-in per origin),

so Microsoft 365 web apps like Teams work in the pane.

Repro

1. Open https://teams.microsoft.com in the in-app browser.
2. It lands on "Classic Teams is no longer available".
3. Click "Use Teams on the web" (/v2) → redirects back to the same page.

Proposed Solution

Make the in-app browser work with Microsoft 365 web apps like Teams:

• present a supported Chromium user-agent (recent Chrome/Edge) so Teams' browser check passes;
• allow third-party cookies (at least opt-in per origin).

Expected: opening https://teams.microsoft.com in the pane loads the Teams web app (as Outlook web already does), so Claude can read/assist with Teams via read_page.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Additional detail — the in-app browser user-agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Claude/1.20186.1 Chrome/148.0.7778.271 Electron/42.5.1 Safari/537.36
navigator.userAgentData.brands: Chromium 148, "Not/A)Brand" 99 — no Google Chrome / Edge brand.
So the pane advertises Electron + a custom Claude token and no Chrome/Edge brand; new Teams web very likely rejects it on that basis (Chromium 148 is current, so it's not a version issue). Overriding the UA to a plain recent Chrome/Edge for such origins would likely fix it.
Env: Claude 1.20186.1, Chromium 148, Electron 42.5.1, Windows 10.

Feature Category

Other

Use Case Example

_No response_

Additional Context

_No response_