接口大运年长改成 365.25 天，和推运脚本同一天（BUG-1321，上游 4d543209）

只改兜底时间线的结束日和进入本运年数这两处。同一大运起止相差 0 天。pytest tests/test_dasha_year_length_alignment.py 2 通过。增长合同仍过。

Co-Authored-By: Grok (agent loop)

docs/BUG_HISTORY.md

@@ -17765,3 +17765,18 @@
 - 复发自：无。
 - 修复版本：分支 `codex/upstream-sync7-20261014`，尚未合入 staging。
 
+## BUG-1321 | 接口里的大运年长和推运脚本差了一点，起止会对不齐
+
+- 状态：fixed-pending-verify
+- 首次发现 / 最近更新：2026-10-14 / 2026-10-14
+- 来源：issue #56。上游 `4d543209`。任务书 T4。
+- 现象：接口的兜底大运和「进入本运几年」用 365.25636 天为一年。同一条时间线的推运脚本用 365.25 天。年限一长，日期会差一天。
+- 触发条件：走兜底大运时间线，或计算进入当前大运的年数。
+- 根因：两处常量没有跟着推运脚本改。同步第六轮漏了上游 10-03 的这一处。
+- 修复：这两处改成 365.25，与推运脚本相同。其它大运系统的年长不动。
+- 验证：`tests/test_dasha_year_length_alignment.py` 2 通过。同一大运起止相差 0 天。158 年的旧常量会落到下一天，新常量不会。
+- 防复发：兜底时间线必须和推运脚本的起止是同一天；进入本运的年数按 365.25 除。
+- 相关记录：BUG-1320。
+- 复发自：无。
+- 修复版本：分支 `codex/upstream-sync7-20261014`，尚未合入 staging。
+

scripts/jyotish_api_server.py

@@ -6378,7 +6378,7 @@ class JyotishAPIHandler(BaseHTTPRequestHandler, VedastroEvidenceMixin, SynastryM
         periods = []
         current = birth_dt
         for lord in DASHA_ORDER:
-            end_date = current + timedelta(days=period_years * 365.25636)
+            end_date = current + timedelta(days=period_years * 365.25)
             periods.append({
                 'lord': lord,
                 'years': period_years,
@@ -7398,7 +7398,7 @@ class JyotishAPIHandler(BaseHTTPRequestHandler, VedastroEvidenceMixin, SynastryM
             current_idx, current_md = analyzer.find_current(timeline, today)
             antardashas = analyzer.build_antardasha(current_md)
             current_ad = analyzer.find_current_sub(antardashas, today)
-            years_into_md = max(0.0, (today - current_md['start']).days / 365.25636)
+            years_into_md = max(0.0, (today - current_md['start']).days / 365.25)
             five_levels = enhanced.calculate_five_level_dasha(current_md['lord'], years_into_md)
             formatted_timeline = [self._format_datetime_period(period) for period in timeline]
             formatted_antardashas = [self._format_datetime_period(period) for period in antardashas]

tests/test_dasha_year_length_alignment.py

@@ -0,0 +1,62 @@
+"""BUG-1321: the API fallback dasha year matches dasha_analyzer's 365.25 days.
+
+Upstream 4d543209. The two 365.25636 constants in the API server made the
+fallback timeline and the years-into-mahadasha figure drift from the analyzer.
+"""
+
+from __future__ import annotations
+
+import importlib.util
+import os
+import sys
+from datetime import datetime, timedelta
+
+SCRIPTS = os.path.join(os.path.dirname(__file__), "..", "scripts")
+if SCRIPTS not in sys.path:
+    sys.path.insert(0, SCRIPTS)
+
+from dasha_analyzer import build_dasha_timeline, lon_to_nakshatra  # noqa: E402
+
+
+def _api_handler():
+    """Reuse the existing unbound handler helper. Do not add another forgery site."""
+    path = os.path.join(os.path.dirname(__file__), "test_api_server_security.py")
+    spec = importlib.util.spec_from_file_location("_api_security_helpers_dasha", path)
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module._handler()
+
+
+def test_fallback_timeline_matches_analyzer_to_the_day() -> None:
+    birth = datetime(2000, 1, 1)
+    nak_info, progress, _pada = lon_to_nakshatra(0.0)
+    timeline, _elapsed, _remaining, _lord = build_dasha_timeline("2000-01-01", nak_info, progress)
+    handler = _api_handler()
+    years = timeline[0]["years"]
+    periods = handler._fallback_dasha_periods(birth, "generic", {"years": years * 9})
+    assert periods[0]["lord"] == timeline[0]["lord"]
+    assert periods[0]["start"] == timeline[0]["start"].strftime("%Y-%m-%d")
+    assert periods[0]["end"] == timeline[0]["end"].strftime("%Y-%m-%d")
+    fallback_days = (
+        datetime.strptime(periods[0]["end"], "%Y-%m-%d")
+        - datetime.strptime(periods[0]["start"], "%Y-%m-%d")
+    ).days
+    analyzer_days = (timeline[0]["end"].date() - timeline[0]["start"].date()).days
+    assert fallback_days - analyzer_days == 0
+
+    long_periods = handler._fallback_dasha_periods(birth, "generic", {"years": 1422})
+    expected = (birth + timedelta(days=158 * 365.25)).strftime("%Y-%m-%d")
+    stale = (birth + timedelta(days=158 * 365.25636)).strftime("%Y-%m-%d")
+    assert expected != stale
+    assert long_periods[0]["end"] == expected
+
+
+def test_years_into_mahadasha_uses_the_analyzer_year() -> None:
+    birth = datetime(2000, 1, 1)
+    today = datetime(2003, 1, 1)
+    handler = _api_handler()
+    layer = handler._compute_vimshottari_analysis_layer(birth, 0.0, current_date="2003-01-01")
+    days = (today - birth).days
+    years_into = layer["five_levels"]["mahadasha"]["years_into_period"]
+    assert years_into == days / 365.25
+    assert years_into != days / 365.25636