test: add wallet money-path tests, strengthen billing RED tests

- New test_wallet_money_paths.py (10 tests): is_mint_connection_error,
  classify_redemption_error, store_cashu_transaction success path,
  get_balance, periodic task structure verification
- Fixed test_messages_streaming_no_silent_billing_failure:
  was  (always pass), now properly asserts
  the silent pass pattern must NOT exist
- ruff: all clean, mypy: all clean

10 RED failures (correct), 867 pass, 14 skip

tests/unit/test_wallet_money_paths.py

@@ -0,0 +1,157 @@
+"""Additional money-path coverage tests for wallet.py (86% → target 90%).
+
+Tests error classification, periodic task structure, and token operations.
+"""
+
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+
+# ===========================================================================
+# is_mint_connection_error
+# ===========================================================================
+
+def test_is_mint_connection_error_true() -> None:
+    """Connection errors are detected."""
+    from routstr.wallet import is_mint_connection_error
+
+    assert is_mint_connection_error(ConnectionRefusedError("refused")) is True
+    assert is_mint_connection_error(TimeoutError("timeout")) is True
+
+
+def test_is_mint_connection_error_false() -> None:
+    """Non-connection errors are not flagged."""
+    from routstr.wallet import is_mint_connection_error
+
+    assert is_mint_connection_error(ValueError("bad data")) is False
+    assert is_mint_connection_error(KeyError("missing key")) is False
+    assert is_mint_connection_error(RuntimeError("something broke")) is False
+    assert is_mint_connection_error(AttributeError("no attr")) is False
+    # OSError is NOT a connection error unless it's a subclass
+    assert is_mint_connection_error(OSError("generic")) is False
+
+
+# ===========================================================================
+# classify_redemption_error
+# ===========================================================================
+
+def test_classify_redemption_error_token_consumed() -> None:
+    """Token already spent returns token_consumed classification."""
+    from routstr.wallet import TokenConsumedError, classify_redemption_error
+
+    result = classify_redemption_error(
+        TokenConsumedError("Token was already redeemed")
+    )
+    assert result is not None
+    assert result[0] == "token_consumed"
+    assert result[1] == 500
+
+
+def test_classify_redemption_error_mint_connection() -> None:
+    """Mint connection error is classified correctly."""
+    from routstr.wallet import classify_redemption_error
+
+    result = classify_redemption_error(
+        ConnectionRefusedError("Connection refused")
+    )
+    assert result is not None
+    # Should classify as mint_connection or return error tuple
+    assert isinstance(result, tuple)
+    assert len(result) >= 3
+
+
+def test_classify_redemption_error_unclassified() -> None:
+    """Generic errors are classified as cashu_error with 400 status."""
+    from routstr.wallet import classify_redemption_error
+
+    result = classify_redemption_error(ValueError("unexpected"))
+    # classify_redemption_error classifies all unrecognized errors
+    # as cashu_error with a generic message
+    assert result is not None
+    assert result[0] == "cashu_error"
+    assert result[1] == 400
+
+
+# ===========================================================================
+# Store readiness: store_cashu_transaction succeeds
+# ===========================================================================
+
+@pytest.mark.asyncio
+async def test_store_cashu_transaction_succeeds_normally() -> None:
+    """Normal store_cashu_transaction returns True on success."""
+    from routstr.core.db import store_cashu_transaction
+
+    with patch("routstr.core.db.create_session") as mock_create:
+        mock_session = AsyncMock()
+        mock_session.commit = AsyncMock()
+        mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+        mock_session.__aexit__ = AsyncMock(return_value=None)
+        mock_create.return_value = mock_session
+
+        result = await store_cashu_transaction(
+            token="cashuAtest",
+            amount=1000,
+            unit="sat",
+            typ="in",
+            request_id="req-test",
+        )
+
+        assert result is True
+
+
+# ===========================================================================
+# get_balance
+# ===========================================================================
+
+@pytest.mark.asyncio
+async def test_get_balance_returns_integer() -> None:
+    """get_balance returns an integer balance from wallet."""
+    from routstr.wallet import get_balance
+
+    mock_wallet = Mock()
+    mock_wallet.available_balance = Mock(amount=50000)
+    mock_wallet.load_mint = AsyncMock()
+    mock_wallet.load_proofs = AsyncMock()
+
+    with patch("routstr.wallet.Wallet.with_db", return_value=mock_wallet):
+        balance = await get_balance("sat")
+        assert isinstance(balance, int)
+        assert balance == 50000
+
+
+# ===========================================================================
+# Periodic task structure verification
+# ===========================================================================
+
+def test_periodic_payout_has_loop_and_error_handling() -> None:
+    """periodic_payout runs in a loop with error handling."""
+    import inspect
+
+    from routstr import wallet
+
+    source = inspect.getsource(wallet.periodic_payout)
+    assert "while True" in source
+    assert "except" in source, "Must have error handling"
+
+
+def test_periodic_refund_sweep_has_error_handling() -> None:
+    """Refund sweep catches errors to stay alive."""
+    import inspect
+
+    from routstr import wallet
+
+    source = inspect.getsource(wallet.periodic_refund_sweep)
+    assert "while True" in source
+    assert "except" in source, "Must have error handling"
+
+
+def test_periodic_routstr_fee_payout_structure() -> None:
+    """Fee payout loop handles missing LN address gracefully."""
+    import inspect
+
+    from routstr import wallet
+
+    source = inspect.getsource(wallet.periodic_routstr_fee_payout)
+    # Returns early if ROUTSTR_LN_ADDRESS not set
+    assert "ROUTSTR_LN_ADDRESS" in source
+    assert "return" in source or "skip" in source.lower()

tests/unit/test_zero_cost_fallback.py

@@ -141,6 +141,10 @@ def test_messages_streaming_no_silent_billing_failure() -> None:
 
     handle_streaming_messages_completion uses `except Exception: pass`
     for the finalize path, silently dropping the billing attachment.
+    After the fix, this catch block must either:
+    - Log at CRITICAL level with the error details
+    - Propagate the error to surface an HTTP 500
+    - Release reserved balance and refund the token
     """
     from routstr.upstream.base import BaseUpstreamProvider
 
@@ -148,13 +152,20 @@ def test_messages_streaming_no_silent_billing_failure() -> None:
         BaseUpstreamProvider.handle_streaming_messages_completion
     )
 
-    # The finalize_without_usage has except Exception: pass
-    # This should either propagate or log failure
+    # After fix: the silent pass in finalize_without_usage must be replaced
+    # The fix must include at least one of: CRITICAL logging, error propagation,
+    # or balance release in the error path.
+
+    # The silent pass must NOT exist around billing finalization
+    silent_pass_exists = False
     for segment in source.split("except Exception:"):
-        if "finalize_without_usage" in segment or "finalize" in segment:
-            if "pass" in segment[:100]:
+        if "adjust_payment_for_tokens" in segment:
+            if "pass" in segment[:150]:
+                silent_pass_exists = True
                 break
 
-    # Check if the silent pass pattern exists
-    has_silent_finalize = "finalize_without_usage()" in source
-    assert has_silent_finalize or True  # documentation
+    assert not silent_pass_exists, (
+        "FIX REQUIRED: finalize_without_usage in messages streaming "
+        "silently swallows billing errors with `except Exception: pass`. "
+        "User gets unbilled inference with no log record."
+    )