fix(nostr): prevent nip-07 fallback from overwriting concurrent login

- Added a check in `ensureActiveSignerForPubkey` to verify if a valid signer (e.g. NIP-46) was registered during the extension wait period.
- Modified `nip07Permissions.js` to respect global timeout overrides for structured permission requests, fixing flaky tests.
- Added regression test `tests/nostr-signer-race.test.mjs` to simulate the race condition.

Co-authored-by: PR0M3TH3AN <[email protected]>

js/nostr/client.js

@@ -2642,6 +2642,12 @@ export class NostrClient {
       }
     }
 
+    // Check if a signer appeared while we were waiting (e.g. NIP-46 or concurrent NIP-07 logic)
+    const recheckedSigner = resolveActiveSigner(normalizedPubkey);
+    if (recheckedSigner && typeof recheckedSigner.signEvent === "function") {
+      return recheckedSigner;
+    }
+
     if (!extension) {
       return existingSigner;
     }

js/nostr/nip07Permissions.js

@@ -275,7 +275,7 @@ export async function requestEnablePermissions(
     // If we fall back to standard enable() (null), allow the full user interaction time.
     const variantTimeoutOverrides = options
       ? {
-          timeoutMs: 3000,
+          timeoutMs: Math.min(3000, getEnableVariantTimeoutMs()),
           retryMultiplier: 1,
         }
       : {

tests/nostr-signer-race.test.mjs

@@ -0,0 +1,65 @@
+
+import "./test-helpers/setup-localstorage.mjs";
+import assert from "node:assert/strict";
+import test from "node:test";
+import { NostrClient, setActiveSigner, getActiveSigner } from "../js/nostr/client.js";
+
+const HEX_PUBKEY = "a".repeat(64);
+
+test("ensureActiveSignerForPubkey prefers concurrent login over late extension injection", async () => {
+  // 1. Setup Environment
+  const originalWindow = global.window;
+  global.window = {};
+
+  try {
+    const client = new NostrClient();
+    client.pubkey = HEX_PUBKEY;
+    // Pre-condition: Cache permissions to trigger the waitForNip07Extension logic
+    client.extensionPermissionCache.add("sign_event");
+
+    // Mock a NIP-46 signer that might be set during the race
+    const mockNip46Signer = {
+      type: "nip46",
+      pubkey: HEX_PUBKEY,
+      signEvent: async () => ({ id: "mock-signed" }),
+      nip04: { encrypt: async () => "enc", decrypt: async () => "dec" }
+    };
+
+    // Mock the NIP-07 extension that appears late
+    const mockExtension = {
+      getPublicKey: async () => HEX_PUBKEY,
+      signEvent: async () => ({ id: "ext-signed" }),
+      nip04: { encrypt: async () => "ext-enc", decrypt: async () => "ext-dec" }
+    };
+
+    // 2. Start the race
+    // Calling ensureActiveSignerForPubkey while window.nostr is missing but permissions exist
+    // causes it to enter waitForNip07Extension loop (polling).
+    const ensurePromise = client.ensureActiveSignerForPubkey(HEX_PUBKEY);
+
+    // 3. Simulate Concurrent Login (e.g. NIP-46 restore completes)
+    // We wait a small amount to ensure ensureActiveSignerForPubkey has started polling
+    await new Promise(resolve => setTimeout(resolve, 50));
+
+    setActiveSigner(mockNip46Signer);
+
+    // 4. Simulate Extension Loading late
+    global.window.nostr = mockExtension;
+
+    // 5. Await result
+    const resultSigner = await ensurePromise;
+
+    // 6. Assertions
+    const finalActiveSigner = getActiveSigner();
+
+    // We expect the NIP-46 signer to be preserved and not overwritten by the NIP-07 fallback
+    assert.equal(finalActiveSigner.type, "nip46", "Race condition! NIP-46 signer was overwritten by NIP-07 fallback.");
+    assert.equal(resultSigner.type, "nip46", "Returned signer should be the NIP-46 one.");
+  } finally {
+    if (originalWindow) {
+      global.window = originalWindow;
+    } else {
+      delete global.window;
+    }
+  }
+});