fix(consultation): 外网证据按盘+日期缓存，超时取消前台任务

BUG-727：同日 VedAstro 快照零等待，跨日先用旧的并后台刷新；join 超时必须 cancel，budget 不超过 2×join。BUG-728：western_evidence_packet 无读取点，默认不再进咨询响应。jyotish_api_server.py 未增长（11334→11291）。

tests/conftest.py

@@ -5,6 +5,8 @@ from __future__ import annotations
 import sys
 from pathlib import Path
 
+import pytest
+
 ROOT = Path(__file__).resolve().parents[1]
 SCRIPTS = str(ROOT / "scripts")
 WORKBUDDY_SKILL_SCRIPTS = ".workbuddy/skills/jyotish-vedic-astrology/scripts"
@@ -38,6 +40,12 @@ def pytest_runtest_setup() -> None:
     ensure_project_scripts_first()
 
 
+@pytest.fixture(autouse=True)
+def _isolate_vedastro_snapshot_cache(tmp_path_factory, monkeypatch) -> None:
+    cache_dir = tmp_path_factory.mktemp("vedastro_snapshot_cache")
+    monkeypatch.setenv("JYOTISH_VEDASTRO_SNAPSHOT_CACHE_DIR", str(cache_dir))
+
+
 def pytest_collection_modifyitems(items) -> None:
     for item in items:
         if item.fspath.basename == "test_api_server_security.py" and item.name.startswith(SLOW_API_SECURITY_PREFIXES):