Fix chat captcha after rebase: restore HCAPTCHA_SITE_KEY global and captcha container

- _Layout.cshtml: emit window.HCAPTCHA_SITE_KEY from HCaptcha:SiteKey config
- ChatWidget.vue: destructure captchaContainerEl ref, add hidden container div
- chat-module.js: use whenHcaptchaReady() from hcaptcha-form.js for robustness
  (waits for hcaptcha.js to load before rendering the invisible widget)

Author: BenjaminMichaelis

EssentialCSharp.Web/Views/Shared/_Layout.cshtml

@@ -188,6 +188,7 @@
         window.TRYDOTNET_ORIGIN = @Json.Serialize(Configuration["TryDotNet:Origin"]);
         window.BUILD_LABEL = @Json.Serialize(buildLabel);
         window.ENABLE_CHAT_WIDGET = @Json.Serialize(!Context.Request.Path.StartsWithSegments("/Identity"));
+        window.HCAPTCHA_SITE_KEY = @Json.Serialize(Configuration["HCaptcha:SiteKey"]);
     </script>
     <script src="~/dist/assets/site-shell.js" type="module" asp-append-version="true"></script>
 </body>

EssentialCSharp.Web/src/components/ChatWidget.vue

@@ -11,6 +11,7 @@ const {
     isTyping,
     chatMessagesEl,
     chatInputField,
+    captchaContainerEl,
     openChatDialog,
     closeChatDialog,
     clearChatHistory,
@@ -189,6 +190,8 @@ const {
                             Type your question and press Enter or click send. Maximum 500 characters.
                         </div>
                     </form>
+                    <!-- Invisible hCaptcha widget attachment point — no visible UI in invisible mode -->
+                    <div ref="captchaContainerEl" style="display:none;" aria-hidden="true"></div>
                 </div>
             </div>
         </div>

EssentialCSharp.Web/wwwroot/js/chat-module.js

@@ -144,9 +144,17 @@ export function useChatWidget() {
     async function ensureCaptchaWidget() {
         if (!window.HCAPTCHA_SITE_KEY) throw new Error('Captcha is not configured.');
         await nextTick();
-        if (!window.hcaptcha?.render) throw new Error('Captcha script is not ready.');
         if (captchaWidgetId !== null) return;
 
+        // Wait for hcaptcha.js to load — uses the shared whenHcaptchaReady queue from hcaptcha-form.js
+        await new Promise((resolve, reject) => {
+            const timeout = setTimeout(() => reject(new Error('Captcha script is not ready.')), 10000);
+            window.EssentialCSharp.HCaptcha.whenHcaptchaReady(() => {
+                clearTimeout(timeout);
+                resolve();
+            });
+        });
+
         captchaWidgetId = window.hcaptcha.render(captchaContainerEl.value, {
             sitekey: window.HCAPTCHA_SITE_KEY,
             size: 'invisible',