Migrate frontend to Svelte 5 runes semantics

frontend/src/components/llm/ProviderConfig.svelte

@@ -11,25 +11,26 @@
   import { requestApi } from "../../lib/api";
   import { addToast } from "../../lib/toasts.js";
 
-  /** @type {Array} */
-  export let providers = [];
-  export let onSave = () => {};
+  let {
+    providers = [],
+    onSave = () => {},
+  } = $props();
 
-  let editingProvider = null;
-  let showForm = false;
+  let editingProvider = $state(null);
+  let showForm = $state(false);
 
-  let formData = {
+  let formData = $state({
     name: "",
     provider_type: "openai",
     base_url: "https://api.openai.com/v1",
     api_key: "",
     default_model: "gpt-4o",
     is_active: true,
-  };
+  });
 
-  let testStatus = { type: "", message: "" };
-  let isTesting = false;
-  let togglingProviderIds = new Set();
+  let testStatus = $state({ type: "", message: "" });
+  let isTesting = $state(false);
+  let togglingProviderIds = $state(new Set());
 
   function isMultimodalModel(modelName) {
     const token = (modelName || "").toLowerCase();
@@ -162,7 +163,7 @@
     <button
       type="button"
       class="bg-blue-600 text-white px-4 py-2 rounded hover:bg-blue-700 transition"
-      on:click|preventDefault={() => {
+      onclick={() => {
         resetForm();
         showForm = true;
       }}
@@ -285,7 +286,7 @@
           <button
             type="button"
             class="px-4 py-2 border rounded hover:bg-gray-50 flex-1"
-            on:click|preventDefault={() => {
+            onclick={() => {
               showForm = false;
             }}
           >
@@ -295,14 +296,14 @@
             type="button"
             class="px-4 py-2 bg-gray-600 text-white rounded hover:bg-gray-700 flex-1"
             disabled={isTesting}
-            on:click|preventDefault={testConnection}
+            onclick={testConnection}
           >
             {isTesting ? $t.llm.testing : $t.llm.test}
           </button>
           <button
             type="button"
             class="px-4 py-2 bg-blue-600 text-white rounded hover:bg-blue-700 flex-1"
-            on:click|preventDefault={handleSubmit}
+            onclick={handleSubmit}
           >
             {$t.llm.save}
           </button>
@@ -340,14 +341,14 @@
           <button
             type="button"
             class="text-sm text-blue-600 hover:underline"
-            on:click|preventDefault|stopPropagation={() => handleEdit(provider)}
+            onclick={() => handleEdit(provider)}
           >
             {$t.common.edit}
           </button>
           <button
             type="button"
             class={`text-sm ${provider.is_active ? "text-orange-600" : "text-green-600"} hover:underline`}
-            on:click|preventDefault|stopPropagation={() => toggleActive(provider)}
+            onclick={() => toggleActive(provider)}
             disabled={togglingProviderIds.has(provider.id)}
           >
             {#if togglingProviderIds.has(provider.id)}