Option D

Invisible chrome: ⌘K switcher + peek strip

No persistent navigation at all. The inbox owns the entire window; press ⌘K (or click the hint in the title bar) for the workspace palette, and hover the badge dots in the corner for the peek strip.

DriveChina
DC
DriveChina
  • WZ
    Wei Zhang
    BYD Seal import quote — revised — Attached the updated landed-cost sheet with the new freight rate…
    9:41
  • PV
    Port of Vancouver
    Container MSKU-884 cleared customs — Your shipment has been released and is available for pickup…
    9:12
  • MT
    Marie Tremblay
    Re: Test drive this Saturday? — Perfect, 10am works. Should I bring anything besides my license…
    8:47
  • St
    Stripe
    Payout of $12,480.00 on the way — Your payout is expected to arrive in your bank account by…
    Yesterday
  • LC
    Liu Chen
    Q3 allocation — need your confirmation — We can hold 6 units of the Han EV at the current price until Friday…
    Yesterday

How it works

  • The tenant SPA gets essentially the whole window — the only permanent chrome is a slim drag bar with the workspace name and a ⌘K hint.
  • ⌘K opens a shell-level palette: fuzzy-jump to any workspace (with live unread/awaiting counts inline), plus cross-workspace actions — open overview, compose in…, search everywhere.
  • A collapsed peek strip sits bottom-right: one badge dot per workspace, expanding to names on hover, one click to switch. It's ambient awareness without a rail.
  • ⌘1–9 remains the muscle-memory fast path; Esc dismisses everything.

Assessment

  • Pros: the least chrome of any option — nothing competes with the already-dense inbox UI; the palette scales to any workspace count and doubles as a cross-workspace action surface; cheap to build as a shell overlay.
  • Cons: low discoverability — a founder who doesn't know ⌘K is stranded; the peek strip floats over inbox content (bottom-right collisions); no overview page unless paired with another option.
  • Best when: paired with A or C rather than standing alone. The ⌘K switcher is paradigm-neutral and worth shipping regardless of which top-level model wins.
  • Shell notes: the palette must be shell UI (a bundled overlay WebContentsView or the title-bar webContents), not injected into tenant pages — remote tabs keep the minimal preload, and the palette reads the same bootstrap + counts the shell already has.