tray tooltips: tilt persists while portal is open; PRV|NXT pinned to corners — TDD

- TrayTooltip adds .tt-active to the .tray-role-card / .tray-sig-card cell while its tooltip is open & removes it on _hide. The hover-tilt selectors gain .tt-active alongside :hover, :focus so the card stays tilted while the user is hovering the portal itself rather than the cell.
- #id_tooltip_portal: .fyi-prev / .fyi-next pinned to the bottom corners w. 1rem outside the panel (bottom: -1rem; left/right: -1rem) — same anchor the @stat-block-shared mixin uses for fan / sig / sea, restated here since the portal isn't covered by that mixin.
- 2 new TrayTooltipSpec specs (.tt-active added on hover, removed on _hide; for both role & sig branches).

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/static_src/scss/_gameboard.scss

@@ -138,6 +138,22 @@ body.page-gameboard {
         .btn { margin: 0; }
     }
 
+    // Tray sig-card tooltip (Phase 2) — PRV / NXT btns pinned to the bottom
+    // corners of the portal, 1rem outside the panel so the btn centres land
+    // exactly on the corners. The shared @stat-block-shared mixin in
+    // _card-deck.scss already does this for fan / sig / sea contexts; the
+    // portal isn't covered by that mixin so we re-state the rules here.
+    .fyi-prev,
+    .fyi-next {
+        display: inline-flex;
+        position: absolute;
+        bottom: -1rem;
+        margin: 0;
+        z-index: 70;
+    }
+    .fyi-prev { left:  -1rem; }
+    .fyi-next { right: -1rem; }
+
     &.active { display: block; }
 }