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/NpcGroupModal.tsx

@@ -0,0 +1,133 @@
+import React, { useEffect, useMemo, useState } from 'react';
+import { createPortal } from 'react-dom';
+
+import { DEFAULT_NPC_GROUP_COLOR } from '../../shared/npcs/npcGroups';
+import type { ProjectNpcGroup } from '../../shared/types';
+import editorStyles from '../editor/EditorApp.module.css';
+import { useEditorI18n } from '../editor/i18n/EditorI18nContext';
+import { Button, Input } from '../shared/ui/controls';
+
+import styles from './NpcGroupModal.module.css';
+
+type NpcGroupModalProps = {
+  open: boolean;
+  initial: ProjectNpcGroup | null;
+  siblingNames: string[];
+  onClose: () => void;
+  onSave: (input: { name: string; color: string }) => Promise<void>;
+};
+
+function normalizeName(input: string): string {
+  return input.trim().toLowerCase();
+}
+
+export function NpcGroupModal({ open, initial, siblingNames, onClose, onSave }: NpcGroupModalProps) {
+  const { t } = useEditorI18n();
+  const [name, setName] = useState('');
+  const [color, setColor] = useState(DEFAULT_NPC_GROUP_COLOR);
+  const [saving, setSaving] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    if (!open) return;
+    setName(initial?.name ?? '');
+    setColor(initial?.color ?? DEFAULT_NPC_GROUP_COLOR);
+    setSaving(false);
+    setError(null);
+  }, [initial, open]);
+
+  useEffect(() => {
+    if (!open) return;
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [onClose, open]);
+
+  const trimmed = name.trim();
+  const nameOk = trimmed.length >= 1;
+  const nameDup = useMemo(() => {
+    if (!nameOk) return false;
+    const key = normalizeName(trimmed);
+    const except = normalizeName(initial?.name ?? '');
+    return siblingNames.some((n) => {
+      const nk = normalizeName(n);
+      return nk === key && nk !== except;
+    });
+  }, [initial?.name, nameOk, siblingNames, trimmed]);
+
+  const canSave = nameOk && !nameDup && !saving;
+
+  if (!open) return null;
+
+  return createPortal(
+    <>
+      <button
+        type="button"
+        aria-label={t('common.close')}
+        onClick={onClose}
+        className={editorStyles.modalBackdrop}
+      />
+      <div role="dialog" aria-modal="true" className={editorStyles.modalDialog}>
+        <div className={editorStyles.modalHeader}>
+          <div className={editorStyles.modalTitle}>{initial ? t('npcs.editGroup') : t('npcs.addGroup')}</div>
+          <button
+            type="button"
+            aria-label={t('common.close')}
+            onClick={onClose}
+            className={editorStyles.modalClose}
+          >
+            ×
+          </button>
+        </div>
+
+        <div className={editorStyles.fieldGrid}>
+          <div className={editorStyles.fieldLabel}>{t('npcs.groupName')}</div>
+          <div className={styles.nameColorRow}>
+            <input
+              type="color"
+              className={styles.colorInput}
+              value={color}
+              onChange={(e) => setColor(e.target.value)}
+              aria-label={t('npcs.groupColor')}
+            />
+            <Input value={name} onChange={setName} placeholder={t('npcs.groupName')} />
+          </div>
+          {!nameOk ? <div className={editorStyles.fieldError}>{t('npcs.groupNameRequired')}</div> : null}
+          {nameDup ? <div className={editorStyles.fieldError}>{t('npcs.groupNameDup')}</div> : null}
+        </div>
+
+        {error ? <div className={editorStyles.fieldError}>{error}</div> : null}
+
+        <div className={editorStyles.modalFooter}>
+          <Button onClick={onClose} disabled={saving}>
+            {t('common.cancel')}
+          </Button>
+          <Button
+            variant="primary"
+            disabled={!canSave}
+            onClick={() => {
+              if (!canSave) return;
+              void (async () => {
+                setSaving(true);
+                setError(null);
+                try {
+                  await onSave({ name: trimmed, color });
+                  onClose();
+                } catch (e) {
+                  setError(e instanceof Error ? e.message : String(e));
+                } finally {
+                  setSaving(false);
+                }
+              })();
+            }}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
+      </div>
+    </>,
+    document.body,
+  );
+}