refactor: remove unused hide_missing_ids functionality

- Remove hide_missing_ids parameter from all database functions
- Remove hide_missing_ids from API routes and query parameters
- Remove hide_missing_ids filtering logic from SQLite queries
- Update all tests to remove hide_missing_ids assertions
- Clean up codebase since internalTransactionId extraction is now fixed

This functionality was added as a workaround for missing internalTransactionId
values, but we've now fixed the root cause by properly extracting transaction
IDs from raw data during sync, making this workaround unnecessary.

leggend/api/routes/transactions.py

@@ -18,9 +18,6 @@ async def get_all_transactions(
     summary_only: bool = Query(
         default=True, description="Return transaction summaries only"
     ),
-    hide_missing_ids: bool = Query(
-        default=True, description="Hide transactions without internalTransactionId"
-    ),
     date_from: Optional[str] = Query(
         default=None, description="Filter from date (YYYY-MM-DD)"
     ),
@@ -50,7 +47,6 @@ async def get_all_transactions(
             min_amount=min_amount,
             max_amount=max_amount,
             search=search,
-            hide_missing_ids=hide_missing_ids,
         )
 
         # Get total count for pagination info (respecting the same filters)
@@ -61,7 +57,6 @@ async def get_all_transactions(
             min_amount=min_amount,
             max_amount=max_amount,
             search=search,
-            hide_missing_ids=hide_missing_ids,
         )
 
         # Get total count for pagination info
@@ -126,9 +121,6 @@ async def get_all_transactions(
 async def get_transaction_stats(
     days: int = Query(default=30, description="Number of days to include in stats"),
     account_id: Optional[str] = Query(default=None, description="Filter by account ID"),
-    hide_missing_ids: bool = Query(
-        default=True, description="Hide transactions without internalTransactionId"
-    ),
 ) -> APIResponse:
     """Get transaction statistics for the last N days from database"""
     try:
@@ -146,7 +138,6 @@ async def get_transaction_stats(
             date_from=date_from,
             date_to=date_to,
             limit=None,  # Get all matching transactions for stats
-            hide_missing_ids=hide_missing_ids,
         )
 
         # Calculate stats