feat: add settlement contract boundary

tests/test_contracts_settlement.py

@@ -0,0 +1,61 @@
+"""US-006 tests: Solana contract boundary for stake, payment, and settlement."""
+
+from meshnet_contracts import LocalSolanaContracts
+
+
+def test_node_stake_is_reflected_in_registry():
+    """A node can submit stake and read the updated registry balance."""
+    contracts = LocalSolanaContracts()
+
+    receipt = contracts.registry.submit_stake("node-wallet-a", 500)
+
+    assert receipt["cluster"] == "local-test-validator"
+    assert contracts.registry.get_wallet("node-wallet-a").stake_balance == 500
+    assert contracts.registry.has_minimum_stake("node-wallet-a", minimum_stake=100)
+
+
+def test_client_can_fund_api_key_with_testnet_sol():
+    """A client can fund an API key account and read the available balance."""
+    contracts = LocalSolanaContracts()
+
+    receipt = contracts.payment.fund_api_key("api-key-a", lamports=2_000)
+
+    assert receipt["cluster"] == "local-test-validator"
+    assert contracts.payment.get_balance("api-key-a").lamports == 3_000
+
+
+def test_epoch_settlement_debits_clients_and_rewards_nodes_and_validator():
+    """Settlement distributes native token rewards according to recorded work."""
+    contracts = LocalSolanaContracts(cost_per_layer_token_lamport=2)
+    contracts.payment.fund_api_key("api-key-a", lamports=1_000)
+    contracts.payment.record_attribution(
+        session_id="session-a",
+        api_key="api-key-a",
+        node_wallet="node-wallet-a",
+        layer_start=0,
+        layer_end=15,
+        tokens=10,
+    )
+    contracts.payment.record_attribution(
+        session_id="session-a",
+        api_key="api-key-a",
+        node_wallet="node-wallet-b",
+        layer_start=16,
+        layer_end=31,
+        tokens=10,
+        speed_score=2.0,
+    )
+
+    result = contracts.settlement.settle_epoch(
+        epoch=1,
+        validator_wallet="validator-wallet",
+        validator_reward_share_bps=1_000,
+    )
+
+    assert result.client_debits == {"api-key-a": 640}
+    assert result.node_rewards == {"node-wallet-a": 96, "node-wallet-b": 192}
+    assert result.validator_rewards == {"validator-wallet": 32}
+    assert contracts.payment.get_balance("api-key-a").lamports == 1_360
+    assert contracts.settlement.get_token_balance("node-wallet-a") == 96
+    assert contracts.settlement.get_token_balance("node-wallet-b") == 192
+    assert contracts.settlement.get_token_balance("validator-wallet") == 32