Adds expense approval workflow

Implements expense approval functionality, allowing superusers to review and approve or reject expense entries.

This includes:
- Filtering account balance calculations and user balance calculations to only include cleared journal entries.
- Adding API endpoints to retrieve pending expense entries and approve/reject them.
- Updating the UI to display pending expenses to superusers and provide actions to approve or reject them.

This ensures better control over expenses within the system.

crud.py

@@ -313,14 +313,17 @@ async def get_journal_entries_by_user(
 
 
 async def get_account_balance(account_id: str) -> int:
-    """Calculate account balance (debits - credits for assets/expenses, credits - debits for liabilities/equity/revenue)"""
+    """Calculate account balance (debits - credits for assets/expenses, credits - debits for liabilities/equity/revenue)
+    Only includes entries that are cleared (flag='*'), excludes pending/flagged/voided entries."""
     result = await db.fetchone(
         """
         SELECT
-            COALESCE(SUM(debit), 0) as total_debit,
-            COALESCE(SUM(credit), 0) as total_credit
-        FROM entry_lines
-        WHERE account_id = :id
+            COALESCE(SUM(el.debit), 0) as total_debit,
+            COALESCE(SUM(el.credit), 0) as total_credit
+        FROM entry_lines el
+        JOIN journal_entries je ON el.journal_entry_id = je.id
+        WHERE el.account_id = :id
+        AND je.flag = '*'
         """,
         {"id": account_id},
     )
@@ -360,8 +363,15 @@ async def get_user_balance(user_id: str) -> UserBalance:
         balance = await get_account_balance(account.id)
 
         # Get all entry lines for this account to calculate fiat balances
+        # Only include cleared entries (exclude pending/flagged/voided)
         entry_lines = await db.fetchall(
-            "SELECT * FROM entry_lines WHERE account_id = :account_id",
+            """
+            SELECT el.*
+            FROM entry_lines el
+            JOIN journal_entries je ON el.journal_entry_id = je.id
+            WHERE el.account_id = :account_id
+            AND je.flag = '*'
+            """,
             {"account_id": account.id},
         )