feat: Implement junior fees dashboard and reconciliation

- Add dual-sheet architecture to pull attendance from both adult and junior spreadsheets.
- Introduce parsing rules to isolate juniors (e.g. above '# Treneri', tier 'J').
- Add new endpoints `/fees-juniors` and `/reconcile-juniors` to track junior attendances and match bank payments.
- Display granular attendance components showing adult vs. junior practices.
- Add fee rule configuration supporting custom pricing exceptions for specific months (e.g. Sep 2025) and merging billing periods.
- Add `make sync-2025` target to the Makefile for convenience.
- Document junior fees implementation logic and rules in prompts/outcomes.

Co-authored-by: Antigravity <antigravity@google.com>

tests/test_app.py

@@ -29,6 +29,25 @@ class TestWebApp(unittest.TestCase):
         self.assertIn(b'FUJ Fees Dashboard', response.data)
         self.assertIn(b'Test Member', response.data)
 
+    @patch('app.get_junior_members_with_fees')
+    def test_fees_juniors_route(self, mock_get_junior_members):
+        """Test that /fees-juniors returns 200 and renders the junior dashboard"""
+        # Mock attendance data: one with string symbol '?', one with integer
+        mock_get_junior_members.return_value = (
+            [
+                ('Test Junior 1', 'J', {'2026-01': ('?', 1, 0, 1)}),
+                ('Test Junior 2', 'J', {'2026-01': (500, 4, 1, 3)})
+            ],
+            ['2026-01']
+        )
+        
+        response = self.client.get('/fees-juniors')
+        self.assertEqual(response.status_code, 200)
+        self.assertIn(b'FUJ Junior Fees Dashboard', response.data)
+        self.assertIn(b'Test Junior 1', response.data)
+        self.assertIn(b'? / 1 (J)', response.data)
+        self.assertIn(b'500 CZK / 4 (1A+3J)', response.data)
+
     @patch('app.fetch_sheet_data')
     @patch('app.get_members_with_fees')
     def test_reconcile_route(self, mock_get_members, mock_fetch_sheet):
@@ -67,12 +86,42 @@ class TestWebApp(unittest.TestCase):
             'message': 'Direct Member Payment',
             'sender': 'External Bank User'
         }]
-        
         response = self.client.get('/payments')
         self.assertEqual(response.status_code, 200)
         self.assertIn(b'Payments Ledger', response.data)
         self.assertIn(b'Test Member', response.data)
         self.assertIn(b'Direct Member Payment', response.data)
 
+    @patch('app.fetch_sheet_data')
+    @patch('app.fetch_exceptions')
+    @patch('app.get_junior_members_with_fees')
+    def test_reconcile_juniors_route(self, mock_get_junior, mock_exceptions, mock_transactions):
+        """Test that /reconcile-juniors correctly computes balances for juniors."""
+        mock_get_junior.return_value = (
+            [
+                ('Junior One', 'J', {'2026-01': (500, 4, 2, 2)}),
+                ('Junior Two', 'X', {'2026-01': ('?', 1, 0, 1)})
+            ],
+            ['2026-01']
+        )
+        mock_exceptions.return_value = {}
+        mock_transactions.return_value = [{
+            'date': '2026-01-15',
+            'amount': 500,
+            'person': 'Junior One',
+            'purpose': '2026-01',
+            'message': '',
+            'sender': 'Parent',
+            'inferred_amount': 500
+        }]
+        
+        response = self.client.get('/reconcile-juniors')
+        self.assertEqual(response.status_code, 200)
+        self.assertIn(b'Junior Payment Reconciliation', response.data)
+        self.assertIn(b'Junior One', response.data)
+        self.assertIn(b'Junior Two', response.data)
+        self.assertIn(b'OK', response.data)
+        self.assertIn(b'?', response.data)
+
 if __name__ == '__main__':
     unittest.main()