Close the smaller state inconsistencies (B-96, BET-02, BET-07, WDR-01, WDR-15, TX-16, TX-18, TX-27, TX-29, DEP-15, DEP-16, AUD-30, AUD-46, DAT-22)

- bet/withdrawal routes read listener.client after taking the user lock
- a reduced full-balance withdrawal is checked against the minimum again
- a bet covered only by pending balance answers balance_pending_confirmation
- a recovered bet/withdrawal/payout writes bet_placed/withdrawal_sent/payout_sent
- an abandoned payout clears winner/fee/reserve amounts with payout_txid
- the reconciler pings SSE only for rows it changed
- closing_stalled every 30 minutes past the deadline; closing_waiting_since on /rounds/current
- one refresh per user at a time; a failed refresh no longer ends the Electrum session

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/api/routes/bets.py

@@ -26,16 +26,19 @@ async def create_bet(
     session: AsyncSession = Depends(get_session),
 ) -> BetResponse:
     listener = request.app.state.electrum_listener
-    if listener.client is None:
-        raise http_error(
-            status.HTTP_503_SERVICE_UNAVAILABLE,
-            "network_unavailable",
-            "not connected to the network, try again shortly",
-        )
 
     async with request.app.state.user_locks.acquire(user.id):
+        # B-96 (BET-02): read after the lock is taken — a wait on it across a reconnection
+        # must not hand place_bet the connection that closed while this request queued.
+        client = listener.client
+        if client is None:
+            raise http_error(
+                status.HTTP_503_SERVICE_UNAVAILABLE,
+                "network_unavailable",
+                "not connected to the network, try again shortly",
+            )
         try:
-            participant = await place_bet(session, listener.client, user, network=listener)
+            participant = await place_bet(session, client, user, network=listener)
         except BetError as exc:
             # A rejected broadcast isn't the client's fault — it's the network
             # refusing our transaction, so it answers 502 rather than 400 (B-07).