insert copyright headers for images

server.js

@@ -2,6 +2,7 @@ import express from 'express';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { offlineManifest } from './src/services/offline-manifest.js';
+import { setAppImageCopyright } from './src/services/copyright.js';
 import { config, ensureRuntimeDirectories } from './src/config.js';
 import { openDatabase } from './src/database.js';
 import { createApiRouter } from './src/routes/api.js';
@@ -30,6 +31,7 @@ app.use(express.static(publicDirectory, {
   lastModified: true,
   maxAge: 0,
   setHeaders(res, filePath) {
+    setAppImageCopyright(res, filePath);
     const extension = path.extname(filePath).toLowerCase();
     const authoredAsset = ['.html', '.css', '.js'].includes(extension);
     res.setHeader(