feat: expose per-group refresh plans and cache storage daily

tests/test_storage_cache.py

@@ -0,0 +1,41 @@
+import sys,tempfile,unittest
+from pathlib import Path
+from types import SimpleNamespace
+sys.path.insert(0,str(Path(__file__).resolve().parents[1]/'app'))
+from storage_cache import StorageCache
+
+
+class StorageTests(unittest.TestCase):
+    def test_daily_reads_and_restart_cache(self):
+        with tempfile.TemporaryDirectory() as directory:
+            now=[1000];reads=[]
+            def reader(path):
+                reads.append(path);return SimpleNamespace(total=1000,used=200,free=800)
+            p=Path(directory)/'cache.json'
+            cache=StorageCache(p,reader,lambda:now[0])
+            self.assertEqual(cache.sample()['used'],200)
+            for i in range(20):now[0]+=1;cache.sample()
+            self.assertEqual(len(reads),1)
+            restored=StorageCache(p,reader,lambda:now[0]);restored.sample()
+            self.assertEqual(len(reads),1)
+            now[0]=87400;restored.sample()
+            self.assertEqual(len(reads),2)
+
+    def test_failure_does_not_fabricate_zero_or_retry_each_second(self):
+        with tempfile.TemporaryDirectory() as directory:
+            now=[1000];reads=[]
+            def fail(path):reads.append(path);raise OSError('unavailable')
+            cache=StorageCache(Path(directory)/'cache.json',fail,lambda:now[0])
+            self.assertIsNone(cache.sample());self.assertTrue(cache.error)
+            now[0]+=5;self.assertIsNone(cache.sample())
+            self.assertEqual(len(reads),1)
+
+    def test_failed_read_cooldown_survives_restart(self):
+        with tempfile.TemporaryDirectory() as directory:
+            reads=[]
+            def fail(path):reads.append(path);raise OSError('unavailable')
+            p=Path(directory)/'cache.json'
+            StorageCache(p,fail,lambda:1000).sample()
+            restored=StorageCache(p,fail,lambda:1005)
+            self.assertTrue(restored.error);self.assertIsNone(restored.sample())
+            self.assertEqual(len(reads),1)