Add date/time range support to get_historical_candles

- _fetch_candles now accepts explicit from_ts/to_ts timestamps; falls
  back to count-based window when omitted
- get_historical_candles accepts from_date/to_date in YYYY-MM-DD,
  YYYY-MM-DD HH:MM, or YYYY-MM-DD HH:MM:SS formats (all UTC)
- Yahoo Finance fallback switched from range= to period1/period2 so
  it respects the exact window in both modes
- Added 11 tests covering date range, datetime, end-of-day bump,
  invalid format, count cap, and pattern detection toggle
- gitignore uv.lock (Dockerfile uses pip, not uv sync)

tests/test_server.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import calendar
 import os
+import time
 from unittest.mock import patch
 
 import pytest
@@ -15,6 +17,7 @@ from server import (
     find_top_gainers,
     find_top_losers,
     fundamental_scan,
+    get_historical_candles,
     get_stock_quotes,
     list_fields,
     list_markets,
@@ -468,3 +471,91 @@ class TestSessionTools:
         server._session_cookies = None
         result = clear_session()
         assert "cleared" in result
+
+
+# ---------------------------------------------------------------------------
+# get_historical_candles
+# ---------------------------------------------------------------------------
+
+_MOCK_CANDLES = [
+    {"time": 1746662400, "open": 100.0, "high": 110.0, "low": 95.0,  "close": 105.0, "volume": 1_000_000},
+    {"time": 1746748800, "open": 105.0, "high": 115.0, "low": 100.0, "close": 108.0, "volume": 1_200_000},
+    {"time": 1746835200, "open": 108.0, "high": 112.0, "low": 104.0, "close": 106.0, "volume":   900_000},
+]
+
+
+class TestGetHistoricalCandles:
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_basic_count_based(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL", resolution="D", count=3)
+        mock_fetch.assert_called_once_with("NASDAQ:AAPL", "D", 3, from_ts=None, to_ts=None)
+        assert "NASDAQ:AAPL" in result
+        assert "3 candles" in result
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_from_date_only(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL", from_date="2026-05-08")
+        kw = mock_fetch.call_args.kwargs
+        expected_from = int(calendar.timegm(time.strptime("2026-05-08", "%Y-%m-%d")))
+        assert kw["from_ts"] == expected_from
+        assert kw["to_ts"] is not None  # defaults to now
+        assert "2026-05-08" in result
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_from_and_to_date(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL", from_date="2026-05-08", to_date="2026-05-13")
+        kw = mock_fetch.call_args.kwargs
+        expected_from = int(calendar.timegm(time.strptime("2026-05-08", "%Y-%m-%d")))
+        expected_to = int(calendar.timegm(time.strptime("2026-05-13", "%Y-%m-%d"))) + 86399
+        assert kw["from_ts"] == expected_from
+        assert kw["to_ts"] == expected_to
+        assert "2026-05-08 → 2026-05-13" in result
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_datetime_strings(self, mock_fetch):
+        get_historical_candles("NASDAQ:AAPL", from_date="2026-05-17 14:00", to_date="2026-05-17 14:05")
+        kw = mock_fetch.call_args.kwargs
+        expected_from = int(calendar.timegm(time.strptime("2026-05-17 14:00", "%Y-%m-%d %H:%M")))
+        expected_to = int(calendar.timegm(time.strptime("2026-05-17 14:05", "%Y-%m-%d %H:%M")))
+        assert kw["from_ts"] == expected_from
+        assert kw["to_ts"] == expected_to
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_datetime_with_seconds(self, mock_fetch):
+        get_historical_candles("NASDAQ:AAPL", from_date="2026-05-17 14:00:30", to_date="2026-05-17 14:05:00")
+        kw = mock_fetch.call_args.kwargs
+        expected_from = int(calendar.timegm(time.strptime("2026-05-17 14:00:30", "%Y-%m-%d %H:%M:%S")))
+        assert kw["from_ts"] == expected_from
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_date_only_to_date_end_of_day(self, mock_fetch):
+        # date-only to_date should be bumped to end of that day (23:59:59)
+        get_historical_candles("NASDAQ:AAPL", from_date="2026-05-08", to_date="2026-05-13")
+        kw = mock_fetch.call_args.kwargs
+        midnight = int(calendar.timegm(time.strptime("2026-05-13", "%Y-%m-%d")))
+        assert kw["to_ts"] == midnight + 86399
+
+    @patch("server._fetch_candles", return_value=[])
+    def test_no_data_returned(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL")
+        assert "No historical data" in result
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_invalid_date_format_raises(self, mock_fetch):
+        with pytest.raises(ValueError, match="Unrecognised date"):
+            get_historical_candles("NASDAQ:AAPL", from_date="05/08/2026")
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_count_capped_at_500(self, mock_fetch):
+        get_historical_candles("NASDAQ:AAPL", count=9999)
+        assert mock_fetch.call_args.args[2] == 500
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_detect_patterns_included_by_default(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL")
+        assert "Pattern Detection" in result
+
+    @patch("server._fetch_candles", return_value=_MOCK_CANDLES)
+    def test_detect_patterns_disabled(self, mock_fetch):
+        result = get_historical_candles("NASDAQ:AAPL", detect_patterns=False)
+        assert "Pattern Detection" not in result