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/lib/i18n/locales/en/translation.json

@@ -110,7 +110,7 @@
     }
   },
   "nav": {
-    "newChat": "New chat",
+    "newChat": "Ask temetro",
     "patients": "Patients",
     "appointments": "Appointments",
     "invoices": "Invoices",
@@ -749,7 +749,9 @@
       "ring": "Ring",
       "invited": "Invited",
       "join": "Join",
-      "toastTitle": "{{name}} invited you to a call"
+      "toastTitle": "{{name}} invited you to a call",
+      "accept": "Accept",
+      "decline": "Decline"
     },
     "schedule": {
       "cta": "Schedule meeting",
@@ -764,6 +766,11 @@
       "saving": "Scheduling…",
       "failedTitle": "Couldn't schedule meeting",
       "failedBody": "Please try again."
+    },
+    "calendarEmptyHint": "Schedule a meeting to see it on this day.",
+    "upcoming": {
+      "title": "Upcoming",
+      "empty": "No upcoming meetings."
     }
   },
   "messages": {
@@ -816,7 +823,8 @@
       "apptProvider": "Provider",
       "apptPatient": "Patient",
       "apptStatus": "Status"
-    }
+    },
+    "startCall": "Start a call with {{name}}"
   },
   "analysis": {
     "title": "Overview",
@@ -1020,7 +1028,10 @@
       "title": "Chats",
       "untitled": "New chat",
       "empty": "No saved chats yet.",
-      "delete": "Delete chat"
+      "delete": "Delete chat",
+      "open": "Chat history",
+      "search": "Search chats",
+      "startNew": "Start new chat"
     },
     "suggestions": {
       "schedule": "Show today's schedule",

frontend/lib/nav.ts

@@ -10,9 +10,9 @@ import {
   Mail,
   NotebookPen,
   Pill,
-  Plus,
   Receipt,
   Settings,
+  Sparkles,
   Users,
   Video,
 } from "lucide-react";
@@ -54,7 +54,7 @@ export const navItems: NavItem[] = [
   {
     id: "new-chat",
     labelKey: "nav.newChat",
-    icon: Plus,
+    icon: Sparkles,
     link: "/",
     access: "clinical",
   },