fix: address final PWA review findings

src/components/Modal.tsx

@@ -1,4 +1,4 @@
-import { useEffect } from "react";
+import { useEffect, useId } from "react";
 import { createPortal } from "react-dom";
 import { X } from "lucide-react";
 import { cn } from "../lib/format";
@@ -14,6 +14,7 @@ interface ModalProps {
 }
 
 export function Modal({ open, onClose, title, subtitle, children, size = "md", footer }: ModalProps) {
+  const titleId = useId();
   useEffect(() => {
     if (!open) return;
     const onKey = (e: KeyboardEvent) => {
@@ -35,6 +36,9 @@ export function Modal({ open, onClose, title, subtitle, children, size = "md", f
     <div className="fixed inset-0 z-50 flex items-end justify-center sm:items-center">
       <div className="absolute inset-0 bg-slate-900/40 backdrop-blur-sm animate-fade-in" onClick={onClose} />
       <div
+        role="dialog"
+        aria-modal="true"
+        aria-labelledby={title ? titleId : undefined}
         className={cn(
           "relative z-10 flex max-h-[92vh] w-full flex-col overflow-hidden rounded-t-2xl bg-white shadow-2xl animate-slide-up sm:rounded-2xl",
           maxW
@@ -43,7 +47,7 @@ export function Modal({ open, onClose, title, subtitle, children, size = "md", f
         {(title || subtitle) && (
           <div className="flex items-start justify-between gap-3 border-b border-slate-100 px-5 py-4">
             <div className="min-w-0">
-              {title && <h2 className="text-lg font-bold text-slate-900">{title}</h2>}
+              {title && <h2 id={titleId} className="text-lg font-bold text-slate-900">{title}</h2>}
               {subtitle && <p className="mt-0.5 text-sm text-slate-500">{subtitle}</p>}
             </div>
             <button

src/lib/useInstallPrompt.ts

@@ -7,6 +7,32 @@ interface BeforeInstallPromptEvent extends Event {
   userChoice: Promise<{ outcome: "accepted" | "dismissed"; platform: string }>;
 }
 
+const DISMISSED_STORAGE_KEY = "agendamax-install-dismissed";
+
+function hasDismissedPrompt() {
+  try {
+    return window.sessionStorage.getItem(DISMISSED_STORAGE_KEY) === "1";
+  } catch {
+    return false;
+  }
+}
+
+function clearDismissedPrompt() {
+  try {
+    window.sessionStorage.removeItem(DISMISSED_STORAGE_KEY);
+  } catch {
+    // Storage can be unavailable in privacy-restricted browsers.
+  }
+}
+
+function persistDismissedPrompt() {
+  try {
+    window.sessionStorage.setItem(DISMISSED_STORAGE_KEY, "1");
+  } catch {
+    // Storage can be unavailable in privacy-restricted browsers.
+  }
+}
+
 function isStandalone() {
   return window.matchMedia("(display-mode: standalone)").matches ||
     ("standalone" in navigator && Boolean((navigator as Navigator & { standalone?: boolean }).standalone));
@@ -25,7 +51,7 @@ export function useInstallPrompt() {
     return isIOSSafari() ? "ios-instructions" : "unsupported";
   });
   const [deferred, setDeferred] = useState<BeforeInstallPromptEvent | null>(null);
-  const [dismissed, setDismissed] = useState(false);
+  const [dismissed, setDismissed] = useState(() => typeof window !== "undefined" && hasDismissedPrompt());
   const installInFlight = useRef(false);
 
   useEffect(() => {
@@ -37,10 +63,11 @@ export function useInstallPrompt() {
     const onBeforeInstallPrompt = (event: Event) => {
       event.preventDefault();
       setDeferred(event as BeforeInstallPromptEvent);
-      setState("available");
+      if (!hasDismissedPrompt()) setState("available");
     };
     const onInstalled = () => {
       setDeferred(null);
+      clearDismissedPrompt();
       setDismissed(false);
       setState("installed");
     };
@@ -62,7 +89,10 @@ export function useInstallPrompt() {
       await event.prompt();
       const choice = await event.userChoice;
       if (choice.outcome === "accepted") setState("installed");
-      else setDismissed(true);
+      else {
+        persistDismissedPrompt();
+        setDismissed(true);
+      }
     } catch {
       setDeferred(event);
       setState("available");