Add .htaccess SPA fallback for Apache/LiteSpeed (Hostinger)

Fixes a 404 when refreshing deep routes on Hostinger: serves index.html for
any request that isn't a real file/directory so the client-side router handles
the path. vercel.json doesn't apply on Apache hosts. Lives in public/ so Vite
bundles it into dist/.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/.htaccess

@@ -0,0 +1,17 @@
+# SPA fallback for Apache / LiteSpeed (Hostinger).
+# Without this, refreshing a deep route (e.g. /dashboard/accounting) returns a
+# 404 because no static file exists there. This serves index.html for any
+# request that isn't a real file or directory, so the client-side router can
+# handle the route.
+<IfModule mod_rewrite.c>
+  RewriteEngine On
+  RewriteBase /
+
+  # Serve existing files and directories as-is (assets, images, etc.).
+  RewriteCond %{REQUEST_FILENAME} -f [OR]
+  RewriteCond %{REQUEST_FILENAME} -d
+  RewriteRule ^ - [L]
+
+  # Everything else falls back to the SPA entry point.
+  RewriteRule ^ index.html [L]
+</IfModule>