Flatten the selection and the menu highlight; kill the Aero afterglow

Three things looked wrong, three different causes.

The selected row carried a border. 7.css outlines tr.highlighted (#aaddfa) on
top of its fill, and we had been restating that outline in the new blue — so
the band had an edge, and on the cursor row the dotted focus rect made three
concentric outlines around a single row. The reserved 1px border stays (it is
what stops selection from shifting rows) but is transparent in every state;
the fill paints under it, since background-clip is border-box. --w7-sel-bd and
--w7-sel-bd-idle are gone with it.

The context menu highlighted items with 7.css's translucent gradient wash —
the same gradient the ListView selection just dropped. It now uses
--w7-sel-bg, so selection reads identically wherever it appears.

The hover-off animation was button.css bleeding into menu items, which ARE
buttons: button::before is a glow overlay that fades out over a full second,
and menu.css suppresses it with content:none on the :hover arm ONLY — so
leaving an item brought the pseudo back with opacity animating 1 -> 0, a ghost
trailing the pointer. Killing content in every state removes it. Same family,
also fixed: button:focus runs pulse-anim infinitely, and this menu moves real
focus between items for keyboard nav.

menu-probe.ts now checks the highlight too, using hover-probe's :hover ->
.simhover rewrite: it measures colour spread down a text-free strip of a
force-hovered item, so "is it flat?" is a measurement. Verified the check can
fail by injecting the old wash into the built stylesheet — spread 9, exit 2;
the flat fill reads spread 0 at exactly #cbe8f6. The harness lost its
selection outlines and nothing else, in both themes.

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

ui/dev/harness.html

@@ -200,7 +200,10 @@
       </figure>
       <figure class="cell" style="margin:0">
         <figcaption>ours — context-menu.ts output (buttons, divider, accelerator, checkables)</figcaption>
-        <ul role="menu" style="width:200px">
+        <!-- w7-ctx is the app's marker class (flat highlight, no Aero afterglow).
+             It also carries a position:fixed restatement, which the app wants and a
+             review page in normal flow does not — hence the inline static. -->
+        <ul role="menu" class="w7-ctx" style="width:200px;position:static">
           <li role="menuitem"><button type="button">Send to Other Panel</button></li>
           <li role="menuitem"><button type="button">Open</button></li>
           <li role="menuitem"><button type="button">Edit <span>F4</span></button></li>

ui/src/app/skins/7like/7like.css

@@ -137,9 +137,7 @@
      commander convention this app already follows (see the pane-focus model
      below): the band never disappears, only its strength changes. */
   --w7-sel-bg: #cbe8f6;
-  --w7-sel-bd: #26a0da;
   --w7-sel-bg-idle: #dedede;
-  --w7-sel-bd-idle: #c9c9c9;
   /* Tabs (tabs.css). 7.css hardcodes `color: #222` on every tablist button,
      outside its own var system, which is unreadable on the dark surface. */
   --w7-tab-c: #222;
@@ -201,9 +199,7 @@
   --w7-lv-head-bd: var(--w7-el-bd-d);
   --w7-lv-cell-bd: var(--w7-el-bd-d);
   --w7-sel-bg: #2a4a63;
-  --w7-sel-bd: #4a8cbe;
   --w7-sel-bg-idle: #3a3a3a;
-  --w7-sel-bd-idle: #4c4c4c;
   --w7-tab-c: var(--w7-el-c);
   --w7-mn-c: var(--w7-el-c);
   --w7-mn-bd: var(--w7-el-bd-d);
@@ -262,9 +258,7 @@
     --w7-lv-head-bd: var(--w7-el-bd-d);
     --w7-lv-cell-bd: var(--w7-el-bd-d);
     --w7-sel-bg: #2a4a63;
-    --w7-sel-bd: #4a8cbe;
     --w7-sel-bg-idle: #3a3a3a;
-    --w7-sel-bd-idle: #4c4c4c;
     --w7-tab-c: var(--w7-el-c);
     --w7-mn-c: var(--w7-el-c);
     --w7-mn-bd: var(--w7-el-bd-d);
@@ -582,7 +576,7 @@ html.win7 body {
   }
   .win7 table > tbody > tr.highlighted {
     background: var(--w7-sel-bg-idle);
-    border-color: var(--w7-sel-bd-idle);
+    border-color: transparent;
   }
 
   /* ---- Window frame ----
@@ -658,15 +652,15 @@ html.win7 body {
      1px at top and bottom and shoved every row below it down by 2px as the
      cursor moved. Every row reserves that border instead, transparent when not
      selected, so selecting changes colour and nothing else.
-     NOTE: this sits in `skinfix`, which outranks `skin` by LAYER regardless of
-     specificity, so it would also blank 7.css's highlight border — both
-     selected states therefore restate their border-color below. */
+     The border stays TRANSPARENT even when selected: it exists purely to
+     reserve space. 7.css outlines the selected row (#aaddfa) on top of its
+     fill, which stacked a second edge inside the band and, with the cursor
+     row's dotted rect, drew three concentric outlines around one row. The fill
+     paints under the transparent border (background-clip defaults to
+     border-box), so the band still covers the full row. */
   .win7 table > tbody > tr {
     border: 1px solid transparent;
   }
-  .win7 table > tbody > tr.highlighted {
-    border-color: var(--w7-sel-bd-idle);
-  }
 
   /* Pane-focus model (commander convention, matching Win7 Explorer):
      the CURSOR ROW always carries the selection band in BOTH panels —
@@ -679,13 +673,13 @@ html.win7 body {
      The dotted focus rectangle is NOT the focus signal; it is layered on top
      of the band in the focused pane only, the way Win7 drew the keyboard
      focus rect over the selected item.
-     FLAT, not a gradient: 7.css bands the row with --w7-el-grad-h, its Aero
+     FLAT, and only a fill: 7.css bands the row with --w7-el-grad-h, its Aero
      element-hover ramp, which reads as a glossy button rather than a file
-     selection. Explorer used one solid fill and a solid border. Keep the
-     1px border and 7.css's 3px radius — those ARE Explorer's selection box. */
+     selection, and outlines it as well. One solid colour, no edge — the
+     dotted cursor rect is then the only line on the row, which is what makes
+     it legible as the cursor. */
   .win7 table.is-active > tbody > tr.highlighted {
     background: var(--w7-sel-bg);
-    border-color: var(--w7-sel-bd);
   }
 
   /* One dotted rectangle around the ROW; per cell (tr > *) draws a dotted box
@@ -739,6 +733,40 @@ html.win7 body {
     color: var(--w7-mn-check-c);
   }
 
+  /* Menu items: flat highlight, and no Aero afterglow trailing the pointer.
+     Menu items ARE <button>s, so button.css reaches them with three effects
+     that do not belong on a menu:
+     (1) the highlight is 7.css's translucent wash
+         `linear-gradient(#fff9, #e6ecf5cc 90%, #fffc)` + an #aaddfa edge — the
+         same gradient the ListView selection above just dropped;
+     (2) `button::before` is a blue glow overlay whose opacity fades out over
+         a FULL SECOND (`button:not(:hover):before { transition: opacity 1s
+         linear }`). menu.css sets `content: none` on the :HOVER arm only, so
+         the pseudo reappears the instant you leave an item and then fades 1→0
+         — a ghost dragging behind the pointer. Killing `content` in EVERY
+         state is what removes it; suppressing the transition alone would not,
+         because the glow itself is legitimate on real push buttons;
+     (3) `button:focus` runs `pulse-anim` infinitely, and this menu moves REAL
+         focus between items for keyboard nav — so a focused item would breathe.
+     Scoped to the app's own menu (w7-ctx): 7.css's demo menus keep stock Aero. */
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > label {
+    transition: none;
+    animation: none;
+  }
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button::before,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button::after {
+    content: none;
+  }
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button:hover,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button:focus,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > button:focus-visible,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > label:hover,
+  .win7 ul[role='menu'].w7-ctx > li[role='menuitem'] > label:focus-visible {
+    background: var(--w7-sel-bg);
+    border-color: transparent;
+  }
+
   /* ---- Flat buttons (toolbars + the w7-flat escape hatch) ----
      The paint-suppression half of the rule in `skin` (see there for the split).
      It lives in `skinfix` because 7.css restates border-color at (0,3,1) via