Added new modules and updated existing logic

dev/ui-ux/Opus 4.6/src/components/grid-cell/grid-cell.css

@@ -0,0 +1,66 @@
+/* grid-cell — individual shift cell */
+
+.grid-cell-root {
+  width: var(--cell-width);
+  min-width: var(--cell-width);
+  height: 58px;
+  border-right: 1px solid #f1f5f9;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  position: relative;
+  transition: background 0.1s ease;
+}
+.grid-cell-root:hover:not(.cursor-not-allowed) {
+  background-color: #f8fafc;
+}
+
+.grid-cell-compact {
+  height: 42px;
+}
+
+.grid-cell-shift-badge {
+  font-size: 9px;
+  font-weight: 800;
+  padding: 2px 4px;
+  border-radius: 3px;
+  width: 90%;
+  text-align: center;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  margin-bottom: 2px;
+  border: 1px solid rgba(0,0,0,0.06);
+}
+
+.grid-cell-locked-overlay {
+  position: absolute;
+  inset: 0;
+  background: rgba(241, 245, 249, 0.5);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 5;
+}
+
+.grid-cell-tooltip {
+  padding: 10px 12px;
+  max-width: 220px;
+  border: 1px solid #e2e8f0;
+}
+
+/* Weekend + highlight helpers (applied via dynamic class) */
+.grid-cell-bg-weekend { background-color: #f1f5f9 !important; }
+
+.grid-cell-bg-reading-mode {
+  background-color: #fff9c4 !important;
+}
+.grid-cell-bg-reading-mode-intersection {
+  background-color: #fff176 !important;
+}
+
+.grid-cell-col-hovered {
+  background-color: var(--highlight-bg) !important;
+  z-index: 1;
+}