feat: add strategy and backtest services

- strategy_service.py combines opportunity + portfolio signals into
  unified buy/sell/hold recommendations
- backtest_service.py runs walk-forward backtests on historical datasets
  with virtual cash and positions
- CLI adds `strategy` and `backtest` commands with `--decision-interval`
  and other tuning parameters
- Add tests for both services and CLI dispatch
- Update CLAUDE.md with new architecture docs
- Optimize model weights via opportunity optimizer

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_cli.py

@@ -336,6 +336,76 @@ class CLITestCase(unittest.TestCase):
             max_examples=5,
         )
 
+    def test_strategy_dispatches(self):
+        captured = {}
+        with (
+            patch.object(
+                cli, "load_config", return_value={"binance": {"spot_base_url": "https://test", "recv_window": 5000}, "market": {"default_quote": "USDT"}, "opportunity": {"top_n": 10}}
+            ),
+            patch.object(cli, "get_binance_credentials", return_value={"api_key": "k", "api_secret": "s"}),
+            patch.object(cli, "SpotBinanceClient"),
+            patch.object(
+                cli.strategy_service,
+                "generate_trade_signals",
+                return_value={"buy": [{"symbol": "BTCUSDT", "score": 0.82}], "sell": [], "hold": []},
+            ),
+            patch.object(
+                cli, "print_output", side_effect=lambda payload, **kwargs: captured.setdefault("payload", payload)
+            ),
+        ):
+            result = cli.main(["strategy", "-s", "BTCUSDT"])
+        self.assertEqual(result, 0)
+        self.assertEqual(captured["payload"]["buy"][0]["symbol"], "BTCUSDT")
+
+    def test_backtest_dispatches_without_private_client(self):
+        captured = {}
+        config = {"market": {"default_quote": "USDT"}, "opportunity": {}}
+        with (
+            patch.object(cli, "load_config", return_value=config),
+            patch.object(cli, "_load_spot_client", side_effect=AssertionError("backtest should use dataset only")),
+            patch.object(
+                cli.backtest_service,
+                "run_backtest",
+                return_value={"summary": {"total_return_pct": 5.0, "win_rate": 0.6}, "trades": []},
+            ) as backtest_mock,
+            patch.object(
+                cli,
+                "print_output",
+                side_effect=lambda payload, **kwargs: captured.update({"payload": payload, "agent": kwargs["agent"]}),
+            ),
+        ):
+            result = cli.main(
+                [
+                    "backtest",
+                    "/tmp/dataset.json",
+                    "--initial-cash",
+                    "5000",
+                    "--max-positions",
+                    "3",
+                    "--position-size-pct",
+                    "20",
+                    "--commission-pct",
+                    "0.1",
+                    "--lookback",
+                    "12",
+                    "--agent",
+                ]
+            )
+
+        self.assertEqual(result, 0)
+        self.assertEqual(captured["payload"]["summary"]["total_return_pct"], 5.0)
+        self.assertTrue(captured["agent"])
+        backtest_mock.assert_called_once_with(
+            config,
+            dataset_path="/tmp/dataset.json",
+            initial_cash=5000.0,
+            max_positions=3,
+            position_size_pct=0.2,
+            commission_pct=0.001,
+            lookback=12,
+            decision_interval_minutes=None,
+        )
+
     def test_opportunity_optimize_dispatches_without_private_client(self):
         captured = {}
         config = {"market": {"default_quote": "USDT"}, "opportunity": {}}