feat(npcs): add campaign NPCs with relation graph and session overlay

Add a dedicated NPC editor window, directed relations, control/presentation avatar overlay, and ru/en help for the new section.

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

app/renderer/editor/EditorApp.tsx

@@ -967,7 +967,20 @@ export function EditorApp() {
                     }}
                   />
                   <div className={styles.spacer6} />
-                  <Button onClick={() => setMaterialsManagerOpen(true)}>{t('materials.open')}</Button>
+                  <div className={styles.gamePropsButtons}>
+                    <Button onClick={() => setMaterialsManagerOpen(true)}>{t('materials.open')}</Button>
+                    <Button
+                      onClick={() => {
+                        void getDndApi()
+                          .invoke(ipcChannels.windows.openNpcsEditor, {})
+                          .catch((err) => {
+                            console.error('[editor] openNpcsEditor failed', err);
+                          });
+                      }}
+                    >
+                      {t('npcs.open')}
+                    </Button>
+                  </div>
                   <div className={styles.spacer18} />
                   <div className={styles.inspectorTitle}>{t('scenes.inspectorScene')}</div>
                   {state.selectedSceneId ? (