fix(web): leave chat with a document load for chart, ephemeris, and reports

Session URLs are written with history.pushState, so App Router
router.push cannot leave the home page. Sidebar destinations now
assign the document and stash the current conversation for return.

frontend/src/components/app-sidebar.tsx

@@ -18,9 +18,10 @@ import {
   UserRound,
   Users,
 } from "lucide-react";
-import { usePathname, useRouter } from "next/navigation";
+import { usePathname } from "next/navigation";
 import { useEffect, useRef } from "react";
 import type { Ref } from "react";
+import { persistLoginSessionReturn } from "@/lib/chat-session-url";
 import {
   Sidebar,
   SidebarContent,
@@ -102,7 +103,7 @@ export function AppSidebar({
   sessionControls,
   onAccountMenuOpenChange,
   onNewChat,
-  onOpenReports,
+  onOpenReports: _onOpenReports,
   onSelectSession,
   onSelectChart,
   onAddChart,
@@ -113,7 +114,6 @@ export function AppSidebar({
   onOpenLogout,
 }: AppSidebarProps) {
   const { isMobile, setOpen, setOpenMobile, state, viewport } = useSidebar();
-  const router = useRouter();
   const pathname = usePathname();
   const firstSessionRef = useRef<HTMLButtonElement>(null);
   const historyHeadingRef = useRef<HTMLElement>(null);
@@ -149,18 +149,23 @@ export function AppSidebar({
     if (isMobile) setOpenMobile(false);
   }
 
+  function leaveChat(path: "/chart" | "/ephemeris" | "/reports") {
+    persistLoginSessionReturn();
+    window.location.assign(path);
+  }
+
   function handleOpenReports() {
-    onOpenReports();
+    leaveChat("/reports");
     if (isMobile) setOpenMobile(false);
   }
 
   function handleOpenChart() {
-    router.push("/chart");
+    leaveChat("/chart");
     if (isMobile) setOpenMobile(false);
   }
 
   function handleOpenEphemeris() {
-    router.push("/ephemeris");
+    leaveChat("/ephemeris");
     if (isMobile) setOpenMobile(false);
   }