fix: slugify transliterates now much better

src/main/engine/PostEngine.ts

@@ -13,6 +13,7 @@ import { stemText, stemQuery, SupportedLanguage } from './stemmer';
 import { readPostFile as readPostFileShared, type PostFileData } from './postFileUtils';
 import { CliNotifier, NoopNotifier } from './CliNotifier';
 import type { MediaEngine } from './MediaEngine';
+import { slugify } from './slugify';
 
 export interface PostData {
   id: string;
@@ -216,10 +217,7 @@ export class PostEngine extends EventEmitter {
   }
 
   private generateSlug(title: string): string {
-    return title
-      .toLowerCase()
-      .replace(/[^a-z0-9]+/g, '-')
-      .replace(/^-|-$/g, '');
+    return slugify(title);
   }
 
   /**

src/main/engine/ProjectEngine.ts

@@ -6,6 +6,7 @@ import { eq } from 'drizzle-orm';
 import { app } from 'electron';
 import { getDatabase } from '../database';
 import { projects, posts, media, Project, NewProject } from '../database/schema';
+import { slugify } from './slugify';
 
 export interface ProjectData {
   id: string;
@@ -43,10 +44,7 @@ export class ProjectEngine extends EventEmitter {
   }
 
   private generateSlug(name: string): string {
-    return name
-      .toLowerCase()
-      .replace(/[^a-z0-9]+/g, '-')
-      .replace(/^-|-$/g, '');
+    return slugify(name);
   }
 
   /**

src/main/engine/slugify.ts

@@ -0,0 +1,18 @@
+import { transliterate } from 'transliteration';
+
+/**
+ * Generate a URL-safe slug from a string.
+ *
+ * - Transliterates umlauts and accented characters to ASCII equivalents
+ *   using the `transliteration` package for broad Unicode coverage
+ * - Removes non-alphanumeric characters (except hyphens used as separators)
+ * - Separates words with normal hyphens (U+002D)
+ * - Collapses consecutive separators into a single hyphen
+ * - Strips leading/trailing hyphens
+ */
+export function slugify(input: string): string {
+  return transliterate(input)
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, '-')
+    .replace(/^-+|-+$/g, '');
+}