code refactoring, added router, moved download api path

ui/pnpm-lock.yaml

@@ -14,6 +14,9 @@ dependencies:
   lucide-svelte:
     specifier: ^0.323.0
     version: 0.323.0(svelte@4.2.10)
+  svelte-spa-router:
+    specifier: ^4.0.1
+    version: 4.0.1
 
 devDependencies:
   '@sveltejs/vite-plugin-svelte':
@@ -1254,6 +1257,11 @@ packages:
       picomatch: 2.3.1
     dev: true
 
+  /regexparam@2.0.2:
+    resolution: {integrity: sha512-A1PeDEYMrkLrfyOwv2jwihXbo9qxdGD3atBYQA9JJgreAx8/7rC6IUkWOw2NQlOxLp2wL0ifQbh1HuidDfYA6w==}
+    engines: {node: '>=8'}
+    dev: false
+
   /resolve-from@4.0.0:
     resolution: {integrity: sha512-pb/MYmXstAkysRFx8piNI1tGFNQIFA3vkE3Gq4EuA1dF6gHp/+vgZqsCGJapvy8N3Q+4o7FwvquPJcnZ7RYy4g==}
     engines: {node: '>=4'}
@@ -1498,6 +1506,12 @@ packages:
       typescript: 5.3.3
     dev: true
 
+  /svelte-spa-router@4.0.1:
+    resolution: {integrity: sha512-2JkmUQ2f9jRluijL58LtdQBIpynSbem2eBGp4zXdi7aDY1znbR6yjw0KsonD0aq2QLwf4Yx4tBJQjxIjgjXHKg==}
+    dependencies:
+      regexparam: 2.0.2
+    dev: false
+
   /svelte@4.2.10:
     resolution: {integrity: sha512-Ep06yCaCdgG1Mafb/Rx8sJ1QS3RW2I2BxGp2Ui9LBHSZ2/tO/aGLc5WqPjgiAP6KAnLJGaIr/zzwQlOo1b8MxA==}
     engines: {node: '>=16'}