feat: push notifications + iOS share sheet integration

- Web Push API for offline device notifications (VAPID)
- Custom service worker with push + share target handlers
- iOS/Android share sheet support via Web Share Target API
- Dedicated /share page with one-tap send to nearby peer
- Background tab notifications for incoming transfers
- Persistent deviceId per device

web/src/App.tsx

@@ -1,11 +1,13 @@
 import { Routes, Route } from "react-router-dom";
 import Home from "./pages/Home";
 import JoinRoom from "./pages/JoinRoom";
+import Share from "./pages/Share";
 
 export default function App() {
   return (
     <Routes>
       <Route path="/" element={<Home />} />
+      <Route path="/share" element={<Share />} />
       <Route path="/:code" element={<JoinRoom />} />
     </Routes>
   );

web/src/pages/Share.tsx

@@ -0,0 +1,157 @@
+import { useEffect, useState, useCallback } from "react";
+import { useSignaling } from "../hooks/useSignaling";
+import { useStore } from "../stores/useStore";
+import { useProfileStore } from "../stores/useProfileStore";
+import PeerList from "../components/PeerList";
+import ProfileSetup from "../components/ProfileSetup";
+
+interface SharedData {
+  files: File[];
+  text: string;
+}
+
+/** Read shared files/text from the cache stashed by the service worker */
+async function readSharedData(): Promise<SharedData> {
+  const result: SharedData = { files: [], text: "" };
+
+  try {
+    const cache = await caches.open("share-target");
+
+    // Read metadata
+    const metaResponse = await cache.match("/share-target-meta");
+    if (!metaResponse) return result;
+
+    const meta = await metaResponse.json();
+    result.text = meta.text || "";
+
+    // Read files
+    for (let i = 0; i < (meta.count || 0); i++) {
+      const fileResponse = await cache.match(`/share-target-file/${i}`);
+      if (!fileResponse) continue;
+
+      const blob = await fileResponse.blob();
+      const fileName = decodeURIComponent(
+        fileResponse.headers.get("X-File-Name") || `fichier-${i}`,
+      );
+      result.files.push(new File([blob], fileName, { type: blob.type }));
+    }
+
+    // Clean up cache
+    await caches.delete("share-target");
+  } catch (err) {
+    console.error("[share] Failed to read shared data:", err);
+  }
+
+  return result;
+}
+
+export default function Share() {
+  const isSetUp = useProfileStore((s) => s.isSetUp);
+
+  if (!isSetUp) {
+    return <ProfileSetup onDone={() => {}} />;
+  }
+
+  return <ShareConnected />;
+}
+
+function ShareConnected() {
+  const { sendFiles, sendText } = useSignaling();
+  const peers = useStore((s) => s.peers);
+  const setSelectedPeerId = useStore((s) => s.setSelectedPeerId);
+
+  const [shared, setShared] = useState<SharedData | null>(null);
+  const [sent, setSent] = useState(false);
+
+  useEffect(() => {
+    readSharedData().then(setShared);
+  }, []);
+
+  const handlePeerSelect = useCallback(
+    (peerId: string) => {
+      if (!shared || sent) return;
+
+      setSelectedPeerId(peerId);
+
+      if (shared.files.length > 0) {
+        sendFiles(peerId, shared.files);
+      }
+      if (shared.text && shared.files.length === 0) {
+        sendText(peerId, shared.text);
+      }
+
+      setSent(true);
+    },
+    [shared, sent, sendFiles, sendText, setSelectedPeerId],
+  );
+
+  const fileCount = shared?.files.length || 0;
+  const hasText = !!shared?.text;
+
+  return (
+    <div className="min-h-screen bg-gradient-to-b from-slate-950 via-slate-900 to-slate-950">
+      <div className="max-w-lg mx-auto px-4 py-8">
+        {/* Header */}
+        <header className="text-center mb-6">
+          <h1 className="text-3xl font-bold text-white mb-1">
+            Any<span className="text-brand-400">Drop</span>
+          </h1>
+
+          {!shared ? (
+            <p className="text-slate-500 text-sm mt-4">Chargement...</p>
+          ) : sent ? (
+            <div className="mt-6">
+              <div className="text-4xl mb-3">✓</div>
+              <p className="text-brand-400 font-medium">Envoi en cours</p>
+              <a
+                href="/"
+                className="inline-block mt-4 text-sm text-slate-500 hover:text-slate-300 transition-colors"
+              >
+                Retour à l'accueil
+              </a>
+            </div>
+          ) : (
+            <>
+              <p className="text-slate-400 text-sm mt-4">Envoyer à quel appareil ?</p>
+
+              {/* What's being shared */}
+              <div className="mt-3 inline-flex items-center gap-2 px-3 py-1.5 rounded-full bg-slate-800/50 text-xs text-slate-400">
+                {fileCount > 0 && (
+                  <span>
+                    📎 {fileCount} {fileCount > 1 ? "fichiers" : "fichier"}
+                  </span>
+                )}
+                {hasText && !fileCount && <span>💬 Texte</span>}
+                {hasText && fileCount > 0 && <span>+ texte</span>}
+              </div>
+            </>
+          )}
+        </header>
+
+        {/* Peer list — tap to send immediately */}
+        {!sent && shared && (
+          <section>
+            {peers.length === 0 ? (
+              <div className="flex flex-col items-center justify-center py-16 text-slate-500">
+                <div className="text-5xl mb-4">📡</div>
+                <p className="text-lg font-medium">En attente d'appareils...</p>
+                <p className="text-sm mt-2 text-center max-w-xs">
+                  Ouvrez AnyDrop sur l'appareil destinataire.
+                </p>
+              </div>
+            ) : (
+              <div className="flex flex-wrap justify-center gap-6 py-8">
+                <PeerList onPeerSelect={handlePeerSelect} />
+              </div>
+            )}
+          </section>
+        )}
+
+        {/* Footer */}
+        <footer className="text-center text-xs text-slate-600 mt-12">
+          <p>Peer-to-peer · Chiffré · Aucun fichier ne transite par le serveur</p>
+        </footer>
+      </div>
+    </div>
+  );
+}

web/src/sw.ts

@@ -21,6 +21,59 @@ self.addEventListener("activate", (event) => {
   event.waitUntil(self.clients.claim());
 });
 
+// ── Share Target handler ──
+// iOS/Android share sheet sends a POST to /share with files as multipart/form-data.
+// We intercept it, stash the files in a temporary cache, and redirect to the share page.
+
+self.addEventListener("fetch", (event) => {
+  const url = new URL(event.request.url);
+
+  if (url.pathname === "/share" && event.request.method === "POST") {
+    event.respondWith(
+      (async () => {
+        const formData = await event.request.formData();
+        const files = formData.getAll("files") as File[];
+        const text = formData.get("text") as string | null;
+        const sharedUrl = formData.get("url") as string | null;
+
+        // Build the shared text (combine text + url if both present)
+        let sharedText = "";
+        if (text) sharedText += text;
+        if (sharedUrl) sharedText += (sharedText ? "\n" : "") + sharedUrl;
+
+        // Stash files in Cache Storage so the page can retrieve them
+        if (files.length > 0) {
+          const cache = await caches.open("share-target");
+          // Store each file as a cache entry keyed by index
+          for (let i = 0; i < files.length; i++) {
+            const response = new Response(files[i], {
+              headers: {
+                "Content-Type": files[i].type || "application/octet-stream",
+                "X-File-Name": encodeURIComponent(files[i].name),
+              },
+            });
+            await cache.put(`/share-target-file/${i}`, response);
+          }
+          // Store the count
+          await cache.put(
+            "/share-target-meta",
+            new Response(JSON.stringify({ count: files.length, text: sharedText })),
+          );
+        } else if (sharedText) {
+          const cache = await caches.open("share-target");
+          await cache.put(
+            "/share-target-meta",
+            new Response(JSON.stringify({ count: 0, text: sharedText })),
+          );
+        }
+
+        // Redirect to the share page (GET) — the page will read from cache
+        return Response.redirect("/share", 303);
+      })(),
+    );
+  }
+});
+
 // ── Push notifications ──
 
 self.addEventListener("push", (event) => {
@@ -56,13 +109,11 @@ self.addEventListener("notificationclick", (event) => {
 
   event.waitUntil(
     self.clients.matchAll({ type: "window", includeUncontrolled: true }).then((clients) => {
-      // Focus existing tab if open
       for (const client of clients) {
         if (new URL(client.url).pathname === url && "focus" in client) {
           return client.focus();
         }
       }
-      // Otherwise open new tab
       return self.clients.openWindow(url);
     }),
   );

web/vite.config.ts

@@ -41,6 +41,22 @@ export default defineConfig({
             type: "image/png",
           },
         ],
+        share_target: {
+          action: "/share",
+          method: "POST",
+          enctype: "multipart/form-data",
+          params: {
+            title: "title",
+            text: "text",
+            url: "url",
+            files: [
+              {
+                name: "files",
+                accept: ["*/*"],
+              },
+            ],
+          },
+        } as any,
       },
       devOptions: {
         enabled: false,