Dock hover-peek + title-bar menu cleanup + native "Open on startup"

[AllTerrainDeveloper]

Summary

Replaces the dock's legacy + chip with a hover-reveal peek popover, moves a couple of infrequent title-bar actions into the existing three-dots menu, and makes "Open on startup" actually work for native windows (OS Settings, Recycle Bin, plugin-registered native apps). Adds two extension hooks so plugins can render their own thumbnails inside peek cards. A few small admin-bar polish fixes ride along.

Changes

Dock hover-peek (new)

• src/dock-peek/ — fan-out popover anchored to a dock tile. Shows when the tile has ≥1 open window.
• Mini-window cards: faux titlebar (traffic-light dots + page icon + live window title), hash-tinted body. Titlebar background uses --wp-desktop-titlebar-bg-focused so cards inherit the user's WP profile color scheme (the variables are read off .wp-desktop-shell and inlined on the body-attached popover so they cascade correctly).
• Ghost Card — trailing dashed/breathing card for "open new instance." Click → windowManager.openNew() wrapped in document.startViewTransition() so the card morphs into the new window.
• Hover-to-raise on instance cards: pointerenter calls windowManager.focus(win) so the live window jumps to front behind the popover (Mission-Control / Aero-Peek feel).
• Glass material (backdrop-filter: blur(28px) saturate(180%)), capped at min(80vh, 480px) with internal scroll, JS clamp pass to keep the popover inside the viewport.
• Bottom dock: cards lay out as a horizontal reel (200×116 thumbnails) with X-axis scroll instead of a vertical column.
• Native windows get the peek too — singletons render a focus card without a Ghost Card. Built-in renderers ship for OS Settings (tinted hero icon + "System Preferences" + tab chips) and Recycle Bin (trash icon + live count + paper-slips stack when full).
• Replaces the legacy + chip on multi tiles; chip code removed from src/dock.ts.

Title-bar three-dots menu

• New item: "Open in new window" — opens the current iframe URL as a fresh sibling (distinct from "Open another <Page>" which uses the landing URL).
• Moved from controls cluster into the menu: "Reload" and "Open in browser tab".
• Menu now renders for native windows too (with non-iframe-applicable items hidden).

"Open on startup" works for native windows

• New native:<slug> marker form for the saved preference. PHP validator accepts it (slug constrained to ^[a-z0-9_-]+$); portal redirect falls back to admin_url() when it sees the marker (markers aren't HTTP-redirectable).
• JS toggle saves native:${win.id} for native windows; boot flow detects the marker and opens the right window after init. Built-in OS Settings is opened via its local closure; plugin-registered native windows go through nativeWindows.openById.
• "Open on startup" checkbox state now reflects native-marker matches in the menu's refreshStartupCheckState.

Admin-bar polish

• Ask AI + Switch-to-Desktop icons no longer hardcode #72aee6 blue — they color: inherit and pick up the user's profile color scheme.
• ⌘K badge re-centered (inline-flex + 1px optical nudge).
• Fixed PHP fatal: apostrophes inside CSS comments inside $css = '…' were terminating the single-quoted string. Lesson logged in memory.

New hooks (plugin extension points)

Hook	Type	Signature
wp-desktop.dock.peek-card-content	filter	(body: HTMLElement, { window, item }) => HTMLElement
wp-desktop.dock.peek-card-element	filter	(card: HTMLElement, { window, item }) => HTMLElement

peek-card-content swaps just the card body (default mini-window chrome stays). peek-card-element replaces the whole card — plugin owns chrome and click wiring; the wp-desktop-dock-peek__card class must be preserved (the fan-out animation keys off it).

window.wp.hooks.addFilter(
    'wp-desktop.dock.peek-card-content',
    'my-plugin/thumbnail',
    ( body, { window: win } ) => {
        const img = document.createElement( 'img' );
        img.src = `/wp-json/my-plugin/v1/thumbnail/${ win.id }`;
        img.alt = win.config.title;
        return img;
    }
);

Test plan

• Hover the Posts dock icon with multiple Posts windows open — fan-out reel + Ghost Card appear; instance cards hover-raise the matching window; click morphs the card into focus.
• Hover the OS Settings / Recycle Bin tile when open — bespoke thumbnail renderer (gear / trash + count) shows.
• Hover Plugins / Appearance / Tools / Settings (singletons) when open — single focus card, no Ghost Card.
• Move the dock to bottom — peek opens above the icon as a horizontal reel.
• In a window's three-dots menu: Reload, Open in browser tab, Open in new window all work; native windows show the menu with only the relevant items.
• Mark OS Settings as "Open on startup" → reload from the portal → OS Settings auto-opens.
• Switch admin profile color scheme to Midnight / Coffee / Modern → card titlebars + admin-bar Ask AI / Switch icons match the scheme.
• prefers-reduced-motion: no card animations, no breathing pulse, no spring magnify.
• PHPUnit: desktop_mode_validate_default_window_url accepts native:<slug>, rejects native:, native:foo bar, native:foo/bar, native:../etc/passwd.

Files

src/dock-peek/index.ts                                   (new)
src/dock-peek/built-in-renderers.ts                      (new)
assets/css/dock-peek.css                                 (new)
src/dock.ts                                              (peek wiring + chip removal)
src/desktop.ts                                           (boot-flow native default + renderer bootstrap)
src/window/dom.ts                                        (menu item additions, native-window menu unlock)
src/window/index.ts                                      (menu click handlers)
src/window/menus.ts                                      (native-marker check)
src/window-chrome/controls/built-ins.ts                  (removed core/detach + core/reload)
src/hooks.ts                                             (DOCK_PEEK_CARD_CONTENT, DOCK_PEEK_CARD_ELEMENT)
includes/default-window.php                              (native: validator)
includes/portal.php                                      (native: redirect fallback)
includes/admin-bar.php                                   (icon color + ⌘K alignment + apostrophe fix)
includes/assets.php, includes/render.php                 (enqueue dock-peek.css)
docs/javascript-reference.md                             (peek + filters documented)
docs/hooks-reference.md                                  (multi flag wording updated)
tests/vitest/dock-peek.test.ts                           (new — 12 cases)
tests/vitest/window-submenu.test.ts                      (Open in new window cases)
tests/vitest/window-chrome-controls-render.test.ts       (cluster size 6→4)
tests/phpunit/tests/wpDesktopDefaultWindow.php           (3 native: cases)