feat(npcs): add groups, storyline bindings, and Foundry import

Nested NPC groups with color, graph filter, and scene/storyline binding; Foundry worlds/modules import actors into groups; storyline merge asks on NPC name conflicts and reports NPC counts.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/npcs/NpcsEditorApp.module.css

@@ -45,6 +45,27 @@
   background: #0f0f12;
 }
 
+.sideActions {
+  display: flex;
+  gap: 8px;
+  flex-wrap: nowrap;
+  align-items: stretch;
+}
+
+.sideActions > * {
+  flex: 1 1 0;
+  min-width: 0;
+}
+
+.sideActions button {
+  width: 100%;
+  padding-left: 8px;
+  padding-right: 8px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
 .list {
   display: grid;
   gap: 8px;
@@ -272,3 +293,100 @@
 .menuItemDanger:hover {
   background: rgba(239, 68, 68, 0.18);
 }
+
+.groupBlock {
+  display: grid;
+  gap: 4px;
+}
+
+.groupHeader {
+  display: grid;
+  grid-template-columns: auto auto 1fr auto;
+  align-items: center;
+  gap: 6px;
+  padding: 4px 2px;
+  border-bottom: 1px solid var(--stroke);
+  cursor: grab;
+  user-select: none;
+}
+
+.groupHeaderDragging {
+  opacity: 0.55;
+}
+
+.groupDropBefore {
+  box-shadow: inset 0 2px 0 #60a5fa;
+}
+
+.groupDropAfter {
+  box-shadow: inset 0 -2px 0 #60a5fa;
+}
+
+.groupToggle {
+  border: 0;
+  background: transparent;
+  color: var(--text2);
+  cursor: pointer;
+  width: 18px;
+  padding: 0;
+  font-size: 11px;
+}
+
+.groupColorDot {
+  width: 10px;
+  height: 10px;
+  border-radius: 999px;
+  flex-shrink: 0;
+}
+
+.groupTitle {
+  font-size: 12px;
+  font-weight: 800;
+  letter-spacing: 0.3px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.groupMenuBtn {
+  width: 24px;
+  height: 24px;
+  border: 0;
+  border-radius: 6px;
+  background: transparent;
+  color: var(--text2);
+  cursor: pointer;
+}
+
+.groupMenuBtn:hover {
+  background: #27272a;
+  color: var(--text1);
+}
+
+.groupBody {
+  display: grid;
+  gap: 6px;
+  padding: 4px 0 8px 4px;
+  min-height: 8px;
+}
+
+.groupBodyDrop {
+  background: rgba(96, 165, 250, 0.08);
+  border-radius: 8px;
+  outline: 1px dashed rgba(96, 165, 250, 0.45);
+}
+
+.ungroupedSection {
+  display: grid;
+  gap: 4px;
+  margin-top: 4px;
+}
+
+.ungroupedHeader {
+  font-size: 11px;
+  font-weight: 900;
+  letter-spacing: 0.6px;
+  color: var(--text2);
+  padding: 6px 2px 4px;
+  border-bottom: 1px solid var(--stroke);
+}