fix(dashboard): extend rail edge fades to the track clipping edge (#1731)

.changes/dashboard-rail-edge-fade.md

@@ -0,0 +1,6 @@
+---
+type: fix
+area: dashboard
+---
+
+Dashboard rails no longer show a thin strip of the partly visible card past the soft edge fade, and the focus outline of the first or last card in a rail is no longer cut off.

docs/architecture/workspace-dashboard.md

@@ -143,6 +143,10 @@ hooks: `dashboard-hero`, `dashboard-hero-slide` (`data-hero-kind`),
    optional `aspectRatio` (default `'2 / 3'`), optional `testId`.
 2. Behavior: horizontal flex track with `scroll-snap-type: x mandatory`.
 3. Chevron buttons fade in on hover (desktop only via `@media (hover: none)`).
+   Edge fades follow the chevrons' visibility. The track bleeds
+   `--rail-bleed` past the viewport on every side so card focus rings and
+   hover lift are not clipped; the fades are offset by the same variable so
+   they reach the track's clipping edge and no card strip shows beyond them.
 4. Cards are keyboard-focusable router links; `scroll-snap-align: start`
    means arrow-key nav lands on card boundaries.
 5. Image handling: `loading="lazy"`, `decoding="async"`, fallback icon tile

libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.scss

@@ -3,6 +3,11 @@
     --rail-card-width: var(--cover-rail-width, 172px);
     --rail-gap: var(--cover-gap, 14px);
     --rail-radius: 12px;
+    // How far the scrolling track bleeds past the viewport on every side:
+    // room for a card's focus ring (2px outline + 3px offset) plus its 2px
+    // hover lift, so neither is clipped. The track clips partially visible
+    // cards at this outer edge, so the edge fades extend by the same amount.
+    --rail-bleed: 8px;
 }
 
 .rail {
@@ -81,13 +86,14 @@
 
     // Soft edge gradients hint at horizontal scroll without any interaction.
     // Anchored to the viewport so they appear/disappear in sync with the
-    // chevrons' `.rail__chev--visible` state.
+    // chevrons' `.rail__chev--visible` state, but offset by the track bleed
+    // so each fade ends exactly where the track clips the partial card.
     &::before,
     &::after {
         content: '';
         position: absolute;
-        top: 0;
-        bottom: 0;
+        top: calc(-1 * var(--rail-bleed));
+        bottom: calc(-1 * var(--rail-bleed));
         width: 32px;
         pointer-events: none;
         z-index: 1;
@@ -96,7 +102,7 @@
     }
 
     &::before {
-        left: 0;
+        left: calc(-1 * var(--rail-bleed));
         background: linear-gradient(
             to right,
             var(--app-content-bg, #161a22) 0%,
@@ -105,7 +111,7 @@
     }
 
     &::after {
-        right: 0;
+        right: calc(-1 * var(--rail-bleed));
         background: linear-gradient(
             to left,
             var(--app-content-bg, #161a22) 0%,
@@ -135,10 +141,10 @@
     overflow-x: auto;
     overflow-y: hidden;
     scroll-snap-type: x mandatory;
-    scroll-padding-inline-start: 4px;
+    scroll-padding-inline-start: var(--rail-bleed);
     scrollbar-width: none;
-    padding: 4px;
-    margin: -4px;
+    padding: var(--rail-bleed);
+    margin: calc(-1 * var(--rail-bleed));
 
     &::-webkit-scrollbar {
         display: none;