fix: TypeScript error in terminalStyle computed

frontend/src/components/FloatingTerminal.vue

@@ -283,7 +283,7 @@ function stopResize() {
   nextTick(() => fitAddon?.fit())
 }
 
-const terminalStyle = computed(() => {
+const terminalStyle = computed((): Record<string, string> => {
   // Mobile: bottom sheet with dynamic height
   if (isMobile.value) {
     // When keyboard is open, position above it
@@ -304,15 +304,17 @@ const terminalStyle = computed(() => {
   }
 
   // Desktop: floating window
-  const base = {
-    width: `${size.value.w}px`,
-    height: `${size.value.h}px`
-  }
   if (!hasCustomPosition.value) {
-    return { ...base, bottom: '16px', right: '16px' }
+    return {
+      width: `${size.value.w}px`,
+      height: `${size.value.h}px`,
+      bottom: '16px',
+      right: '16px'
+    }
   }
   return {
-    ...base,
+    width: `${size.value.w}px`,
+    height: `${size.value.h}px`,
     top: `${position.value.y}px`,
     left: `${position.value.x}px`,
     bottom: 'auto',