Analysis: Web snippet does not send user agent context

[Copilot]

Investigation into whether the web snippet (shim) sends any user agent context with its telemetry envelopes.

Findings

The snippet does not include user agent in any telemetry it sends. Both envelope paths omit it:

• AI envelopes (aiSupport.ts): Sets ai.device.id, ai.device.type, ai.operation.name, ai.internal.sdkVersion — no ai.user.userAgent
• OneDS envelopes (1dsSupport.ts): Sets timezone (ext.loc.tz) and locale (ext.user.locale) — no user agent

The snippet does read navigator.userAgent already for IE detection in snippet.ts:

function isIE() {
    let nav = navigator;
    if (nav) {
        let userAgent = (nav.userAgent || "").toLowerCase();
        return (userAgent.indexOf("msie") !== -1 || userAgent.indexOf("trident/") !== -1);
    }
    return false;
}

The ai.user.userAgent tag key exists in ContextTagKeys and is used in the OTel span conversion path (spanUtils.ts), but the standard SDK telemetry pipeline via PropertiesPlugin also does not populate it — it only logs navigator.userAgent for internal diagnostics.

No code changes

This PR is investigation-only. If user agent context should be added to snippet envelopes, the changes would be in aiSupport.ts (add to tags["ai.user.userAgent"]) and 1dsSupport.ts (add to ext.device.userAgent in _addUser()).

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[harsimar]

Did not want to make this pr, closing.