Shell 1.9.4: header menus open where their button is, folded bar or not; ProdCom 1.3.3 keeps its filter on a narrow tile

A tile's dropdown menus (ProdCom's Channels, the Timers menu) opened but
never showed under a folded-away title bar — in fullscreen, or with
auto-hide on. The bar carries a backdrop-filter and a transform while
folded, and either one makes a fixed-positioned descendant position
itself against the bar instead of the viewport: the menu landed a
screen-height below its button, inside the tile's overflow. A tile near
the top of the screen showed a misplaced menu; anything lower showed
nothing at all.

The shell now hosts every header menu on the body, under an element
carrying the tile's data-module so a module's scoped CSS still reaches
its items; places it whole inside the viewport; holds a folded bar open
while one of its menus is open (the pointer has to travel down into the
menu); and marks the open menu's button the way the gear is marked.

ProdCom: seven controls need ~175 px of bar, and the shell clips what a
narrow tile cannot fit — the Channels button went with the rest. Below
380 px the six secondary controls fold into a ⋯ menu offering the same
actions, so the filter is the last thing to go.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/MODULE-GUIDE.md

@@ -391,7 +391,8 @@ const menu = moduleApi.header.addMenu({
   build(menuEl) {
     // called on every open with an emptied menu element — fill it with
     // buttons (give them your scoped classes; the container is styled and
-    // fixed-positioned by the shell, so the tile's overflow can't clip it)
+    // positioned by the shell, hosted on the body under an element carrying
+    // your data-module, so your scoped CSS applies and nothing clips it)
   },
 });
 menu.setLabel('Channels (2/4) ▾'); // update the button text any time