fix(nwc): re-add #p to response filter for Alby relay routing

Dropping both `authors` and `#p` from the kind-23195 subscription filter
fixed wallets that don't set those fields the way NIP-47 implies, but
broke purpose-built NWC relays (notably relay.getalby.com/v1) that use
`#p` as the routing key — without it the relay never delivers the
response to our subscription, so the wallet screen sits on a spinner.

Restore `#p: [client pubkey]` in the relay filter. Keep `authors` out
since that field was the one actually causing the broader interop pain.
Spec-compliant responses always carry the `p` tag, so adding it back
does not exclude any conforming wallet. End-to-end authenticity is
still enforced by NIP-04 decryption against the per-connection shared
secret and by the client-side author check in NwcPaymentTracker.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

amethyst/src/main/java/com/vitorpamplona/amethyst/model/nip47WalletConnect/NwcSignerState.kt

@@ -144,6 +144,7 @@ class NwcSignerState(
 
         val filter =
             NWCPaymentQueryState(
+                toUserHex = event.pubKey,
                 replyingToHex = event.id,
                 relay = walletService.relayUri,
             )
@@ -183,6 +184,7 @@ class NwcSignerState(
 
         val filter =
             NWCPaymentQueryState(
+                toUserHex = event.pubKey,
                 replyingToHex = event.id,
                 relay = walletService.relayUri,
             )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/reqCommand/nwc/FilterNWCPaymentsFromRequests.kt

@@ -25,15 +25,28 @@ import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip47WalletConnect.events.LnZapPaymentResponseEvent
 
 // The request event id (#e) is a unique 32-byte identifier — sufficient on
-// its own to match the response. Adding `authors` or `#p` makes the filter
-// strictly stricter at the relay, which causes silent timeouts on services
-// or relays that don't set / index those fields the way NIP-47 expects
-// (e.g. wallets that omit the `p` tag, relays that don't index single-letter
-// tags on ephemeral kinds). Primal's client uses the same minimal filter
-// (kinds + #e), and the wallet's identity is still authenticated end-to-end
-// by NIP-04 decryption against the per-connection shared secret.
-fun filterNWCPaymentsFromRequests(paymentRequests: Set<HexKey>): Filter =
+// its own to match a spec-compliant kind-23195 response. We deliberately keep
+// `authors` out of the filter because some wallet services route through a
+// signer pubkey that differs from the one advertised in the connection URI,
+// which made the previous `authors`-strict filter time out.
+//
+// We DO keep `#p: [client pubkey]` because purpose-built NWC relays
+// (e.g. relay.getalby.com/v1) use the `#p` tag as the routing key — without
+// it the relay never delivers the response to our subscription, even though
+// the event is well-formed. Spec-compliant responses always set `p` to the
+// client pubkey, so including `#p` does not exclude any conforming wallet.
+// The wallet's identity is still authenticated end-to-end by NIP-04
+// decryption against the per-connection shared secret AND by a client-side
+// `event.pubKey == request.p` check in NwcPaymentTracker.
+fun filterNWCPaymentsFromRequests(
+    paymentRequests: Set<HexKey>,
+    fromUsers: Set<HexKey>,
+): Filter =
     Filter(
         kinds = listOf(LnZapPaymentResponseEvent.KIND),
-        tags = mapOf("e" to paymentRequests.sorted()),
+        tags =
+            mapOf(
+                "e" to paymentRequests.sorted(),
+                "p" to fromUsers.sorted(),
+            ),
     )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/reqCommand/nwc/NWCFinderFilterAssemblerSubscription.kt

@@ -52,6 +52,7 @@ fun NWCFinderFilterAssemblerSubscription(
                 noteEvent.walletServicePubKey()?.let {
                     zapPaymentRequestNote.relays.map {
                         NWCPaymentQueryState(
+                            toUserHex = noteEvent.pubKey,
                             replyingToHex = noteEvent.id,
                             relay = it,
                         )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/reqCommand/nwc/NWCPaymentFilterAssembler.kt

@@ -27,11 +27,14 @@ import com.vitorpamplona.quartz.nip01Core.relay.client.INostrClient
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
 
 // This allows multiple screen to be listening to tags, even the same tag.
-// The subscription filter only needs the request event id (#e) — the wallet
-// service's identity is authenticated by NIP-04 decryption against the
-// per-connection shared secret, not by relay-side `authors`/`#p` filtering.
+// The subscription filter carries `#e: [request id]` plus `#p: [client pubkey]`.
+// The `#p` field is the routing key for purpose-built NWC relays (e.g.
+// relay.getalby.com/v1) — dropping it caused those relays to silently never
+// deliver the response. `authors` is intentionally left out because some
+// wallets sign responses with a key different from the URI-advertised one.
 @Stable
 class NWCPaymentQueryState(
+    val toUserHex: HexKey,
     val replyingToHex: HexKey,
     val relay: NormalizedRelayUrl,
 )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/relayClient/reqCommand/nwc/NWCPaymentWatcherSubAssembler.kt

@@ -33,12 +33,13 @@ class NWCPaymentWatcherSubAssembler(
 
         return keys.groupBy { it.relay }.map { relayGroup ->
             val replyingToPayments = relayGroup.value.mapTo(mutableSetOf()) { it.replyingToHex }
+            val aboutUsers = relayGroup.value.mapTo(mutableSetOf()) { it.toUserHex }
 
             if (replyingToPayments.isEmpty()) return null
 
             RelayBasedFilter(
                 relay = relayGroup.key,
-                filter = filterNWCPaymentsFromRequests(replyingToPayments),
+                filter = filterNWCPaymentsFromRequests(replyingToPayments, aboutUsers),
             )
         }
     }