fix(nostr): unblock the signer handshake (priority + decrypt timeouts)

Real-env console (2026-06-15) showed [signer-ready] taking ~48s and every
list decrypt timing out before AND after it. Root mechanism: a priority
inversion on the 2-slot NIP-07 request queue.

- List decrypts run at NIP07_PRIORITY.HIGH; the readiness gate's
  permission/enable handshake ran at NORMAL. So a flood of HIGH-priority
  decrypts jumped ahead of the gate and starved it — the channel never got
  warmed, so the decrypts kept failing. Fix: add NIP07_PRIORITY.CRITICAL
  (above HIGH) and run the permission/enable handshake at CRITICAL so it
  always wins queue ordering.
- Login-time decrypt timeouts were 12-15s even though a healthy
  nip04/nip44 decrypt is local crypto (~1s); the long window was only to
  tolerate a first-grant prompt, which the gate already pre-grants. A 15s
  timeout just monopolizes one of the two queue slots on a doomed call,
  blocking the gate for 15s at a time. Cut blocks/hashtags/subscriptions
  login decrypt timeouts to 6s so slots cycle ~2.5x faster (and the circuit
  breaker trips in ~18s instead of ~45s). Service-level 15s wrappers stay
  as a backstop (now strictly longer than the nip07 layer).

Part of KNOWN_BUGS #0 ("cut the burst, then add a safety net"). Full unit
suite green.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

js/nostr/nip07Permissions.js

@@ -35,6 +35,13 @@ export const DEFAULT_NIP07_PERMISSION_METHODS = Object.freeze([
 ]);
 
 export const NIP07_PRIORITY = Object.freeze({
+  // CRITICAL is reserved for establishing the signer channel itself (the
+  // permission/enable handshake behind the readiness gate). It must outrank
+  // list decryption (HIGH): otherwise a flood of HIGH-priority decrypts jumps
+  // ahead of the gate in the queue and starves it, so the channel never gets
+  // warmed and every decrypt keeps timing out (the real-env ~48s "signer-ready"
+  // — KNOWN_BUGS #0).
+  CRITICAL: 20,
   HIGH: 10,
   NORMAL: 5,
   LOW: 1,
@@ -590,6 +597,9 @@ export async function requestEnablePermissions(
             ...variantTimeoutOverrides,
             // Interactive grant — never gated by (and can heal) the breaker.
             bypassCircuitBreaker: true,
+            // Establishing the channel must outrank list decryption so the
+            // handshake isn't starved by a flood of HIGH-priority decrypts.
+            priority: NIP07_PRIORITY.CRITICAL,
           },
         );
         return true;

js/services/hashtagPreferencesService.js

@@ -1094,7 +1094,7 @@ class HashtagPreferencesService {
     // gate guarantees the extension is ready before decryption starts, so
     // decrypt calls should complete within 1-2s. 5s accommodates slow
     // extensions while still failing fast for scheme fallback.
-    const nip07DecryptTimeoutMs = allowPermissionPrompt ? 12000 : SHORT_TIMEOUT_MS;
+    const nip07DecryptTimeoutMs = allowPermissionPrompt ? 6000 : SHORT_TIMEOUT_MS;
     const signerDecryptOptions = {
       priority: NIP07_PRIORITY.NORMAL,
       timeoutMs: nip07DecryptTimeoutMs,

js/subscriptions.js

@@ -1148,7 +1148,7 @@ class SubscriptionsManager {
     // decrypt calls should complete within 1-2s. 5s accommodates slow
     // extensions while still failing fast enough for scheme fallback.
     const nip07DecryptTimeoutMs = allowPermissionPrompt
-      ? 12000
+      ? 6000
       : SHORT_TIMEOUT_MS;
     const signerDecryptOptions = {
       priority: NIP07_PRIORITY.NORMAL,

js/userBlocks.js

@@ -953,11 +953,13 @@ class UserBlockListManager {
       : allowPermissionPrompt
       ? DECRYPT_TIMEOUT_MS
       : BACKGROUND_DECRYPT_TIMEOUT_MS;
-    // PERF: Previous 3s no-prompt timeout was too aggressive — extensions that
-    // have already granted permission still need time to decrypt. 8s gives a
-    // realistic window while still failing faster than the full 15s interactive
-    // timeout.
-    const nip07DecryptTimeoutMs = allowPermissionPrompt ? 15000 : 8000;
+    // A healthy nip04/nip44 decrypt is local crypto (~1s). The login-time value
+    // was 15s purely to tolerate a slow first-grant prompt — but permissions are
+    // pre-granted by the readiness gate, so a 15s timeout just monopolizes one of
+    // the two NIP-07 queue slots on a doomed call, starving the gate (real-env
+    // ~48s signer-ready — KNOWN_BUGS #0). 6s still tolerates a slow extension
+    // while freeing the slot ~2.5x faster.
+    const nip07DecryptTimeoutMs = allowPermissionPrompt ? 6000 : 6000;
     const emitStatus = (detail) => {
       if (!detail || typeof detail !== "object") {
         return;