[Bug]: aggregate_records (MCP) generates an invalid default ORDER BY SUM(<raw column>) against the grouped derived table on dwsql (Microsoft Fabric Warehouse) → Invalid column name

### What happened?

## Summary

When calling the MCP `aggregate_records` tool with a numeric aggregate (`sum`/`avg`/`min`/`max`) plus `groupby` against a `dwsql` data source (Microsoft Fabric Warehouse), DAB emits a query whose **outer default `ORDER BY` re-applies the aggregate over the *pre-aggregation raw column*** (e.g. `ORDER BY SUM([alias].[amount]) DESC`). The outer query's `FROM` is the grouped derived table, which only exposes the group-by columns and the **aliased** aggregate (`[sum_amount]`), not the raw column `[amount]`. SQL Server therefore fails name resolution with:

```
Msg 207, Level 16, State 1: Invalid column name 'amount'.
```

The inner grouped subquery is correct; only the auto-generated outer `ORDER BY` is wrong. As a result, `sum`/`avg` aggregations via MCP are unusable on Fabric Warehouse.

## Environment

- **Data API builder**: 2.0.9 (`Microsoft.DataApiBuilder 2.0.9`) — also reproduced on 2.0.8
- **Data source `database-type`**: `dwsql`
- **Backend**: Microsoft Fabric Warehouse (SQL analytics endpoint, `*.datawarehouse.fabric.microsoft.com`)
- **Surface**: MCP SQL Server (`runtime.mcp`), tool `aggregate_records`
- **Entity**: a `view` (`dbo.my_view`) with `key-fields` defined
- **OS**: Windows 11

## Configuration (relevant excerpt)

All object names, column names, and connection-string names below are synthetic and minimized for reproduction. The permission setting is also a minimal sample for reproduction only.

```json
{
"data-source": {
"database-type": "dwsql",
"connection-string": "@env('my-connection-string')",
"options": { "set-session-context": false }
},
"runtime": {
"mcp": {
"enabled": true,
"path": "/mcp",
"dml-tools": {
"describe-entities": true,
"read-records": true,
"aggregate-records": true
}
}
},
"entities": {
"my_view": {
"source": { "object": "dbo.my_view", "type": "view", "key-fields": ["id"] },
"permissions": [ { "role": "anonymous", "actions": [ { "action": "read" } ] } ]
}
}
}
```

## Repro steps

1. Point DAB (`database-type: dwsql`) at a Fabric Warehouse and expose a view with a numeric column (here `amount`) and a string column (`category`).
2. Start DAB: `dab start --LogLevel Debug`.
3. Call the MCP `aggregate_records` tool:

```json
{
"method": "tools/call",
"params": {
"name": "aggregate_records",
"arguments": {
"entity": "my_view",
"function": "sum",
"field": "amount",
"groupby": ["category"]
}
}
}
```

4. The call fails with `InternalServerError: Invalid column name 'amount'`.

> Note: passing an explicit `orderby` (e.g. `["category asc"]`) does **not** change the generated SQL — the broken default `ORDER BY SUM() DESC` is still emitted, so there is no client-side workaround.

## Actual generated SQL (from `--LogLevel Debug`)

```sql
SELECT COALESCE('['+STRING_AGG('{'+N'"category":' + ISNULL('"'+STRING_ESCAPE([category],'json')+'"','null')+', '+N'"sum_amount":' + ISNULL(STRING_ESCAPE(CONVERT(NVARCHAR(MAX), [sum_amount]),'json'),'null')+'}',', ')+']','[]')
FROM (
SELECT TOP 101
[dbo_my_view].[category] AS [category],
sum([dbo_my_view].[amount]) AS [sum_amount]
FROM [dbo].[my_view] AS [dbo_my_view]
WHERE 1 = 1
GROUP BY [dbo_my_view].[category]
) AS [dbo_my_view]
ORDER BY SUM([dbo_my_view].[amount]) DESC -- <-- invalid: [amount] is not a column of the derived table
```

The derived table aliased `[dbo_my_view]` only exposes `[category]` and `[sum_amount]`. The outer `ORDER BY SUM([dbo_my_view].[amount])` references the raw, pre-aggregation column `[amount]`, which does not exist at that scope → `Invalid column name 'amount'`.

## Expected behavior

The default ordering should reference the projected aggregate **alias**, not re-aggregate the raw column in the outer scope:

```sql
) AS [dbo_my_view]
ORDER BY [sum_amount] DESC
```

(Equivalently, DAB should either order by the aliased aggregation output or omit the default `ORDER BY` when the client did not request one.)

## Additional context / scoping

- `read_records` on the same entity and the **same column** (`SELECT amount ...`) works correctly — the column and permissions are fine.
- `aggregate_records` with `function: "count"`, `field: "*"` works (it does not reference a raw measure column).
- Only the numeric aggregates (`sum`/`avg`/`min`/`max`) with `groupby` fail, and the failure is entirely in the auto-generated outer `ORDER BY`.
- Running the *intended* query by hand against the Warehouse (grouped subquery + `ORDER BY [sum_amount]`) succeeds, confirming the issue is the generated SQL, not the data/schema/permissions.
- This looks related to the `dwsql` query builder's default order-by generation for aggregations (cf. previous fix "failing MCP aggregate_records tool caused by groupby default value", #3294).

## Error detail

```
fail: Azure.DataApiBuilder.Core.Resolvers.IQueryExecutor[0]
Query execution error due to:
Invalid column name 'amount'.
Microsoft.Data.SqlClient.SqlException (0x80131904): Invalid column name 'amount'.
at Azure.DataApiBuilder.Core.Resolvers.QueryExecutor`1.ExecuteQueryAgainstDbAsync[TResult](...) in /_/src/Core/Resolvers/QueryExecutor.cs:line 296
Error Number: 207, State: 1, Class: 16
```

### Version

2.0.9

### What database are you using?

Azure SQL （dwsql（Microsoft Fabric Warehouse））

### What hosting model are you using?

Local (including CLI)

### Which API approach are you accessing DAB through?

MCP

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct