feat(npcs): inspect cards, Show overlay, and optional external link

Clicking an NPC tile opens description cards (multi-select accordion); Show puts avatars on screen. Optional URL opens a webview tab. Avatar pan in the editor commits on pointer up.

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

app/main/project/zipStore.ts

@@ -66,6 +66,7 @@ import {
   npcDispositionRingColor,
   type NpcDisposition,
 } from '../../shared/types/npcDisposition';
+import { normalizeNpcExternalUrl } from '../../shared/types/npcExternalUrl';
 import { DEFAULT_SCENE_GRID, normalizeSceneGrid } from '../../shared/types/sceneGrid';
 import {
   asPreviewRotationDeg,
@@ -1396,6 +1397,7 @@ export class ZipProjectStore {
       npcId?: NpcId;
       name: string;
       description?: string;
+      externalUrl?: string;
       filePath?: string;
       groupId?: NpcGroupId | null;
       ringColor?: string;
@@ -1477,6 +1479,9 @@ export class ZipProjectStore {
           name,
           avatarAssetId: nextAssetId ?? prev.avatarAssetId,
           description: typeof input.description === 'string' ? input.description : prev.description,
+          ...(input.externalUrl !== undefined
+            ? { externalUrl: normalizeNpcExternalUrl(input.externalUrl) }
+            : {}),
           groupId: resolveGroup(input.groupId, prev.groupId),
           ...(input.ringColor !== undefined
             ? { ringColor: normalizeHexColor(input.ringColor, DEFAULT_PLAYER_RING_COLOR) }
@@ -1503,6 +1508,7 @@ export class ZipProjectStore {
           name,
           avatarAssetId: nextAssetId,
           description: typeof input.description === 'string' ? input.description : '',
+          externalUrl: normalizeNpcExternalUrl(input.externalUrl),
           x: 80 + (count % 4) * 220,
           y: 80 + Math.floor(count / 4) * 200,
           groupId: resolveGroup(input.groupId, null),
@@ -1526,6 +1532,7 @@ export class ZipProjectStore {
     patch: {
       name?: string;
       description?: string;
+      externalUrl?: string;
       groupId?: NpcGroupId | null;
       ringColor?: string;
       disposition?: NpcDisposition;
@@ -1559,6 +1566,9 @@ export class ZipProjectStore {
           ...n,
           ...(name !== undefined ? { name } : {}),
           ...(typeof patch.description === 'string' ? { description: patch.description } : {}),
+          ...(patch.externalUrl !== undefined
+            ? { externalUrl: normalizeNpcExternalUrl(patch.externalUrl) }
+            : {}),
           groupId,
           disposition,
           ringColor:
@@ -2650,6 +2660,7 @@ function normalizeProject(p: Project): Project {
         name,
         avatarAssetId: obj.avatarAssetId,
         description: typeof obj.description === 'string' ? obj.description : '',
+        externalUrl: normalizeNpcExternalUrl((obj as { externalUrl?: unknown }).externalUrl),
         x,
         y,
         groupId: resolveNpcGroupId(obj.groupId, groupIdSet),