fix(pairing): default relay to the transport's nostrrelay, not nostrclient proxy

The nostrclient endpoint is a subscription MULTIPLEXER, not a full relay: its
router forwards a client's EVENT upstream but never returns an OK ack (see
nostrclient/router.py). A transport client that awaits OK on publish therefore
times out ("publish timed out"), so kind-21000 RPCs never complete — verified
on the Sintra: connect succeeded but list_wallets hung, and switching to the
nostrrelay endpoint made the whole flow work (wallet, balance, availability).

default_relay_endpoint now derives from settings.nostr_transport_relays — the
relay the transport actually listens on: use it as-is when already
machine-reachable, or re-home its path on lnbits_baseurl when it's a co-located
loopback relay (the bundled nostrrelay). Validation/localhost-reject and the
pair-dialog pre-fill/hint carry over; wording updated to "transport relay".

227 tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pairing.py

@@ -199,25 +199,41 @@ def build_seed_url(
 _WS_SCHEME_RE = re.compile(r"^wss?://", re.IGNORECASE)
 _LOCAL_HOSTS = {"localhost", "127.0.0.1", "::1", "0.0.0.0"}
 
-# The nostrclient extension serves a public relay-multiplexer websocket at this
-# path (see nostrclient/views_api.py `ws_relay`, gated by config.public_ws).
-NOSTRCLIENT_RELAY_PATH = "/nostrclient/api/v1/relay"
+
+def _baseurl_ws() -> str | None:
+    """`settings.lnbits_baseurl` as a ws(s):// scheme+host (no trailing slash)."""
+    base = (settings.lnbits_baseurl or "").strip().rstrip("/")
+    if base.startswith("https://"):
+        return "wss://" + base[len("https://") :]
+    if base.startswith("http://"):
+        return "ws://" + base[len("http://") :]
+    return None
 
 
 def default_relay_endpoint() -> str | None:
-    """Derive the machine-facing relay from THIS lnbits' own nostrclient proxy
-    endpoint, so operators configure upstream relays once in the nostrclient
-    extension and every seed points at one stable URL (bitspire#70). Built from
-    `settings.lnbits_baseurl` (http→ws, https→wss). Returns None when the base
-    URL is unset. Requires the nostrclient extension's `public_ws` to be on."""
-    base = (settings.lnbits_baseurl or "").strip().rstrip("/")
+    """Derive the machine-facing relay from lnbits' nostr-transport config, so a
+    seed points at the relay the transport ACTUALLY listens on (bitspire#70).
+
+    NOTE: this is the nostr *relay* (a full relay that acks EVENTs), NOT the
+    nostrclient proxy — the client multiplexer forwards subscriptions but never
+    sends `OK`, so a transport client that awaits `OK` on publish times out.
+
+    If the transport relay is already machine-reachable, use it as-is; if it's a
+    co-located loopback relay (the bundled nostrrelay at
+    `ws://localhost:5001/nostrrelay/<id>`), re-home its path on lnbits' public
+    base URL so a remote ATM can reach the same relay. Returns None if neither
+    a transport relay nor a base URL is available."""
+    relays = settings.nostr_transport_relays or []
+    if not relays:
+        return None
+    relay = relays[0]
+    host = (urlparse(relay).hostname or "").lower()
+    if host and host not in _LOCAL_HOSTS and not host.endswith(".localhost"):
+        return relay  # already remote-reachable
+    base = _baseurl_ws()
     if not base:
         return None
-    if base.startswith("https://"):
-        base = "wss://" + base[len("https://") :]
-    elif base.startswith("http://"):
-        base = "ws://" + base[len("http://") :]
-    return base + NOSTRCLIENT_RELAY_PATH
+    return base + urlparse(relay).path
 
 
 def _validate_relay(url: str, field: str) -> None:
@@ -262,11 +278,11 @@ async def pair_spire(
     with a fake client.
 
     `relays` are the relays the spire uses for its *own* events
-    (kind-21000/30078). When omitted, they default to this lnbits' nostrclient
-    proxy endpoint (`default_relay_endpoint`, derived from `lnbits_baseurl`) so
-    operators configure upstream relays once in the extension and every seed
-    points at one stable URL. Every relay (and `bunker_relay`) is validated as a
-    remote-reachable `ws(s)://` URL — a loopback host is rejected (bitspire#70).
+    (kind-21000/30078). When omitted, they default to the relay the transport
+    listens on (`default_relay_endpoint`, from `nostr_transport_relays` re-homed
+    on `lnbits_baseurl`) so a seed points at a relay that actually acks EVENTs.
+    Every relay (and `bunker_relay`) is validated as a remote-reachable
+    `ws(s)://` URL — a loopback host is rejected (bitspire#70).
     `bunker_relay` (the relay baked into `bunker_url`, where the spire reaches
     the bunker) defaults to `relays[0]`; `keystore_passphrase` defaults to the
     lnbits bunker setting. All injectable for tests.
@@ -284,14 +300,14 @@ async def pair_spire(
             "LNBITS_NSEC_BUNKER_KEYSTORE_PASSPHRASE is not set — "
             "cannot mint a spire key"
         )
-    # Default the spire's event relay(s) to this lnbits' nostrclient proxy
-    # endpoint when the caller gives none.
+    # Default the spire's event relay(s) to the transport's own relay (re-homed
+    # on the base URL) when the caller gives none.
     if not relays:
         endpoint = default_relay_endpoint()
         if not endpoint:
             raise PairingError(
-                "no relays given and lnbits_baseurl is unset — cannot derive the "
-                "nostrclient relay endpoint for the seed"
+                "no relays given and none could be derived — set "
+                "nostr_transport_relays (and lnbits_baseurl if it's a loopback relay)"
             )
         relays = [endpoint]