Fix on-prem detection for hybrid mailboxes; record Windows sidecar qualification - #896
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New Outlook on Mac reports accountType "office365" for a hybrid account whose mailbox actually lives on-prem — the value tracks the signed-in Entra identity, not the mailbox host. The old logic let a cloud accountType veto the endpoint evidence, misrouting such mailboxes to the Graph path (which cannot reach an on-prem mailbox). Only the positive "enterprise" ⇒ on-prem signal is now trusted; otherwise a non-Microsoft ewsUrl/restUrl host decides. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018ynzg88ooDpkwtoJo9VtHP
Fills the Windows classic Outlook row of the TRANSPORT.md qualification matrix (WebView2 150, no PNA preflight, no loopback exemption or prompt needed). The macOS row remains pending; it is tracked separately (WKWebView blocks plain-http loopback as mixed content, requiring the HTTPS profile). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018ynzg88ooDpkwtoJo9VtHP
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Two independent items split out of the
feature/ermain-503-addin-sidecar-thread-fetcherbranch (#892) so that PR stays focused on the sidecar fetcher. Both surfaced during Outlook-on-Mac testing.1. Bug fix — on-prem detection for hybrid mailboxes (
detectExchangeOnPrem)New Outlook on Mac reports
accountType: "office365"for a hybrid account whose mailbox actually lives on-prem — the value tracks the signed-in Entra identity, not the mailbox host. The previous logic let a cloudaccountTypeveto the endpoint evidence, so these mailboxes were misrouted to the Graph path, which cannot reach an on-prem mailbox.Fix: only the positive
"enterprise" ⇒ on-premsignal is trusted; otherwise a non-MicrosoftewsUrl/restUrlhost decides. Added a test asserting a non-MicrosoftewsUrlwins over a cloudaccountType; existing cases updated to use cloud endpoints so they still read as not-on-prem.vitest→ 11/11 pass.Independent of the sidecar work; belongs on
mainregardless.2. Docs — Windows classic Outlook transport qualification
Fills the Windows classic Outlook row of the
TRANSPORT.mdqualification matrix from live testing: WebView2 150, no Private-Network-Access preflight, no loopback exemption or permission prompt required. The macOS row stays pending and is tracked separately (WKWebView blocks plain-http loopback as mixed content — ERMAIN-522 adds the HTTPS profile).