feat: show page titles on agent and topic pages

This commit moves the actions bar out of the default template and into the
individual pages so that they can display their titles at the top. this
commit also has pages set the meta title so tabs are labeled nicely.

app/layouts/default.vue

@@ -17,14 +17,6 @@ useKeyboardShortcuts();
     <Sidenav />
     <main
         class="bg-[var(--bg-surface)] flex flex-col h-full w-full border border-solid border-[var(--color-border)] rounded-lg overflow-hidden">
-        <div class="h-14 flex items-center justify-between px-4">
-            <div class="flex items-center gap-2">
-                <button v-if="!sidebarOpen" @click="openSidebar"
-                    class="flex p-2 rounded-lg text-[var(--text-primary)] bg-transparent hover:bg-[var(--color-hover)] transition-colors">
-                    <Icon class="text-5" name="mynaui:panel-left-open" />
-                </button>
-            </div>
-        </div>
         <div class="flex-1 overflow-y-auto">
             <slot />
         </div>