fix: HTML export tojson filter + authenticated file download (v0.14.1)

- Enable minijinja 'json' feature so the tojson filter is available in
  the Memories.html template (was causing 'unknown filter' render error)
- Replace window.location.href downloads with fetch+blob so the
  Authorization header is sent (window.location.href caused 401)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/Cargo.toml

@@ -29,7 +29,7 @@ sysinfo = "0.32"
 image = "0.25"
 oxipng = "9"
 async_zip = { version = "0.0.17", features = ["tokio", "deflate"] }
-minijinja = "2"
+minijinja = { version = "2", features = ["json"] }
 
 [profile.release]
 opt-level = 3

frontend/src/routes/export/+page.svelte

@@ -72,13 +72,28 @@
 		}
 	}
 
+	async function downloadFile(endpoint: string, filename: string) {
+		const token = getToken();
+		const res = await fetch(endpoint, {
+			headers: token ? { Authorization: `Bearer ${token}` } : {}
+		});
+		if (!res.ok) return;
+		const blob = await res.blob();
+		const url = URL.createObjectURL(blob);
+		const a = document.createElement('a');
+		a.href = url;
+		a.download = filename;
+		a.click();
+		URL.revokeObjectURL(url);
+	}
+
 	function downloadZip() {
-		window.location.href = '/api/v1/export/zip';
+		downloadFile('/api/v1/export/zip', 'Gallery.zip');
 	}
 
 	function downloadHtml() {
 		if (localStorage.getItem(HTML_GUIDE_KEY)) {
-			window.location.href = '/api/v1/export/html';
+			downloadFile('/api/v1/export/html', 'Memories.zip');
 		} else {
 			showHtmlGuide = true;
 		}
@@ -87,7 +102,7 @@
 	function confirmHtmlDownload() {
 		localStorage.setItem(HTML_GUIDE_KEY, '1');
 		showHtmlGuide = false;
-		window.location.href = '/api/v1/export/html';
+		downloadFile('/api/v1/export/html', 'Memories.zip');
 	}
 </script>