fix(clipboard): use navigator.clipboard.writeText as primary, arboard as fallback — fixes silent failure on Linux/XWayland

src/lib/pages/DictationPage.svelte

@@ -417,7 +417,9 @@
   async function finaliseTranscription(audioPath = null) {
     if (transcript.trim()) {
       if (settings.autoCopy) {
-        invoke("copy_to_clipboard", { text: transcript }).catch(() => {});
+        navigator.clipboard.writeText(transcript).catch(() => {
+          invoke("copy_to_clipboard", { text: transcript }).catch(() => {});
+        });
       }
 
       const historyId = crypto.randomUUID();
@@ -464,7 +466,11 @@
   }
 
   function copyAll() {
-    if (transcript) invoke("copy_to_clipboard", { text: transcript }).catch(() => {});
+    if (transcript) {
+      navigator.clipboard.writeText(transcript).catch(() => {
+        invoke("copy_to_clipboard", { text: transcript }).catch(() => {});
+      });
+    }
   }
 
   function clearTranscript() {