refactor: purge all remaining crypto/Binance references

- Replace BTCUSDT/SOLUSDT/ETHUSDT with AAPL/MSFT in all test files
- Update backtester default symbol to AAPL
- Update strategy-engine default symbols to US stocks
- Update project description and CLI help text
- Remove empty superpowers docs directory
- Zero crypto references remaining in codebase

1 files changed, 3 insertions, 3 deletions

diff --git a/services/data-collector/tests/test_storage.py b/services/data-collector/tests/test_storage.py
index be85578..ffffa40 100644
--- a/services/data-collector/tests/test_storage.py
+++ b/services/data-collector/tests/test_storage.py
@@ -9,7 +9,7 @@ from shared.models import Candle
 from data_collector.storage import CandleStorage
 
 
-def _make_candle(symbol: str = "BTCUSDT") -> Candle:
+def _make_candle(symbol: str = "AAPL") -> Candle:
     return Candle(
         symbol=symbol,
         timeframe="1m",
@@ -39,11 +39,11 @@ async def test_storage_saves_to_db_and_publishes():
     mock_broker.publish.assert_called_once()
 
     stream_arg = mock_broker.publish.call_args[0][0]
-    assert stream_arg == "candles.BTCUSDT"
+    assert stream_arg == "candles.AAPL"
 
     data_arg = mock_broker.publish.call_args[0][1]
     assert data_arg["type"] == "CANDLE"
-    assert data_arg["data"]["symbol"] == "BTCUSDT"
+    assert data_arg["data"]["symbol"] == "AAPL"
 
 
 @pytest.mark.asyncio