frontend: chat/meetings/messages/settings UX fixes

- settings: keep tab nav on its own row so "Developers" no longer wraps
- chat: show the "Veil active" chip once per conversation, not every turn
- chat: record cards only offer "Click for more" when they have detail
- chat: chat-history panel (pill + sheet) top-left of the AI chat with
  "Start new chat"; rename sidebar "New chat" -> "Ask temetro" (Sparkles)
- meetings: disable past dates, add an Upcoming Meetings list, and use the
  Empty component for empty days; scheduler can be pre-targeted via ?with
- messages: add a call button left of each inbox row -> Meetings (?with)
- toast: add a dismiss (x) button; call invites now ring 30s with "Accept"

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/components/ui/toast.tsx

@@ -7,6 +7,7 @@ import {
   InfoIcon,
   LoaderCircleIcon,
   TriangleAlertIcon,
+  XIcon,
 } from "lucide-react";
 import type React from "react";
 import { cn } from "@/lib/utils";
@@ -163,14 +164,23 @@ function Toasts({
                     />
                   </div>
                 </div>
-                {toast.actionProps && (
-                  <Toast.Action
-                    className={buttonVariants({ size: "xs" })}
-                    data-slot="toast-action"
+                <div className="flex shrink-0 items-center gap-1">
+                  {toast.actionProps && (
+                    <Toast.Action
+                      className={buttonVariants({ size: "xs" })}
+                      data-slot="toast-action"
+                    >
+                      {toast.actionProps.children}
+                    </Toast.Action>
+                  )}
+                  <Toast.Close
+                    aria-label="Dismiss"
+                    className="flex size-6 items-center justify-center rounded-md text-muted-foreground transition-colors hover:bg-accent hover:text-foreground"
+                    data-slot="toast-close"
                   >
-                    {toast.actionProps.children}
-                  </Toast.Action>
-                )}
+                    <XIcon className="size-4" />
+                  </Toast.Close>
+                </div>
               </Toast.Content>
             </Toast.Root>
           );