fix(workspace): keep the macOS header clear of the lights when zoomed out (#1815)

* fix(workspace): keep the macOS header clear of the lights when zoomed out

App zoom scales CSS pixels but not the native traffic lights. At zoom
-3/-4 the header column starts near 29 window pixels, so Back and the
playlist switcher slid under the lights, and the 27px header band let
the lights overlap the context panel below.

A shell-level TrafficLightsClearanceDirective now publishes the lights'
clearance in CSS pixels (84 x 48 window pixels, from the page zoom
factor) on macOS. The header band grows to the vertical clearance (the
rail starts its first link at the same band, replacing the rail's own
zoom listener), and the header's leading padding grows to the
horizontal clearance less the rail column. Both equal the default
layout at 100 %; Windows/Linux and the phone layout are unchanged. The
native position is shared with the main process as
MACOS_TRAFFIC_LIGHTS_POSITION.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* test(workspace): pass the header clearance poll labels as options

Equivalent to the string form, which Playwright 1.62 also accepts, but
explicit in every version (Greptile review).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* test(workspace): check the header switcher before history exists

Since the header's history fallback, a list reached by navigation
leads with Back. The macOS check now takes the switcher on the first
page, which has nothing to go back to, and Back on a detail page.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: 4gray <fourgray@proton.me>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture/workspace-shell.md

@@ -390,15 +390,32 @@ The Electron window hides the native title bar on all desktop platforms
 (`titleBarStyle: 'hidden'` in `apps/electron-backend/src/app/app.ts`):
 
 1. macOS keeps the native traffic lights (`titleBarOverlay: true`,
-   `trafficLightPosition`); the renderer draws no window buttons. The lights
-   sit in the 56 px header band above the rail, so the macOS rail
-   (`.app-rail.is-macos`) starts its first link at 56 px: level with the
-   content area and the dashboard hero, with its hover surface clear of the
-   lights. App zoom scales CSS pixels but not the lights, so the rail
-   publishes the page zoom factor (`outerWidth / innerWidth`, refreshed on
-   `resize`) as `--rail-zoom-factor` and keeps at least 48 window pixels when
-   zoomed out. `window-controls.e2e.ts` checks the alignment and the gap at
-   default and minimum zoom on macOS.
+   `trafficLightPosition` from `MACOS_TRAFFIC_LIGHTS_POSITION` in
+   `@iptvnator/shared/interfaces`); the renderer draws no window buttons.
+   The lights sit in the header band (`--workspace-header-band`, 56 px) over
+   the rail and the header's leading padding. The macOS rail
+   (`.app-rail.is-macos`) starts its first link below the band: level with
+   the content area and the dashboard hero, with its hover surface clear of
+   the lights. The header's content starts 84 window pixels from the
+   window's left edge (60 px rail plus 24 px padding). macOS 26 ends the
+   lights at 76 (earlier releases at 68), which is where Back's left edge
+   sits at 100 % because of its 8 px pull-in.
+
+   App zoom (see "Zoom level") scales CSS pixels but not the lights. On
+   macOS, `TrafficLightsClearanceDirective` on `.workspace-shell` reads the
+   page zoom factor (`outerWidth / innerWidth`, refreshed on `resize`) and
+   publishes the clearance in CSS pixels as `--traffic-lights-clear-x` (84
+   window pixels) and `--traffic-lights-clear-y` (48: the lights' bottom
+   plus a gap). Zoomed out, the band grows to the vertical clearance, so the
+   lights never overlap the content area. The header's leading padding grows
+   to the horizontal clearance, less the rail column
+   (`--workspace-header-lights-inset`). At 100 % both match the default
+   layout. Off macOS nothing is published and the defaults apply. The phone
+   layout, which puts the rail in a row above the header, ignores the
+   inset. `window-controls.e2e.ts` ("macOS traffic lights") checks the rail
+   alignment, the first header control (the switcher on the first page,
+   which has no history fallback yet, then a detail page's Back) and the
+   content top at default and minimum zoom.
 2. Windows and Linux use renderer-drawn window controls
    (`app-window-controls`, `libs/ui/components/src/lib/window-controls/`).
    `frame` is intentionally left untouched so native resize borders and