[Bug] Sync materialized view is never chosen by transparent rewrite on 4.1.3, even for queries identical to the MV definition

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/doris/issues?q=is%3Aissue) and found no similar issues.

### Version

4.1.3

### What's Wrong?

On Doris 4.1.3 (1 FE / 2 BE), synchronous materialized views in `FINISHED` state are never selected by transparent rewrite. `EXPLAIN` / `EXPLAIN VERBOSE` always show the base table being scanned — including for queries whose shape is character-for-character identical to the MV definition.

**Case 1: aggregate sync MV on a DUPLICATE KEY table is never hit**

```sql
-- Base table (simplified; real table uses AUTO PARTITION BY RANGE on DATE_TRUNC(ingest_time, 'day')):
CREATE TABLE tick_dirty_minute (
source_topic VARCHAR(255) NOT NULL,
source_partition INT NOT NULL,
source_offset BIGINT NOT NULL,
...
)
DUPLICATE KEY(source_topic, source_partition, source_offset, ...)
AUTO PARTITION BY RANGE (DATE_TRUNC(ingest_time, 'day')) ()
DISTRIBUTED BY HASH(source_topic, source_partition) BUCKETS AUTO;

CREATE MATERIALIZED VIEW mv_tick_dirty_source_watermark AS
SELECT
source_topic AS dirty_source_topic,
source_partition AS dirty_source_partition,
MAX(source_offset) AS latest_source_offset
FROM tick_dirty_minute
GROUP BY source_topic, source_partition
ORDER BY dirty_source_topic, dirty_source_partition;
-- SHOW ALTER TABLE MATERIALIZED VIEW => State: FINISHED

-- Query with the same shape as the MV definition:
EXPLAIN SELECT
source_topic AS dirty_source_topic,
source_partition AS dirty_source_partition,
MAX(source_offset) AS latest_source_offset
FROM tick_dirty_minute
GROUP BY source_topic, source_partition
ORDER BY dirty_source_topic, dirty_source_partition;
-- => TABLE: db.tick_dirty_minute(tick_dirty_minute), PREAGGREGATION: ON
-- The 20M-row base table is fully scanned; the MV index is never chosen.
```

Also tried, with no effect:
- `SET pre_materialized_view_rewrite_strategy = FORCE_IN_RBO;`
- `enable_materialized_view_rewrite` is `true` (default)
- A second aggregate sync MV (`MIN_BY`/`MAX_BY`/`SUM`/`COUNT` OHLC rollup grouped by day/symbol/minute) on another DUPLICATE KEY table shows the same behavior: FINISHED but never selected, even for a query textually identical to the MV definition.

**Case 2: creating a minimal sync MV fails with a confusing error**

```sql
CREATE TABLE tmp_mv_probe (k1 VARCHAR(64) NOT NULL, k2 INT NOT NULL, v BIGINT NOT NULL)
DUPLICATE KEY(k1, k2)
DISTRIBUTED BY HASH(k1) BUCKETS 1
PROPERTIES('replication_num'='2');

CREATE MATERIALIZED VIEW mv_probe AS
SELECT k1, k2, MAX(v) AS max_v FROM tmp_mv_probe GROUP BY k1, k2;
-- => ERROR 1105 (HY000): errCode = 2, detailMessage = Duplicate column name 'k1'
```

There is no duplicate column in the statement. (If un-aliased GROUP BY key columns are intentionally rejected here, the error message is misleading.)

**Anything else:** the production base tables use `AUTO PARTITION BY RANGE(DATE_TRUNC(...))` and one of them has a `GENERATED ALWAYS AS` column — unclear whether these affect materialized index selection, but Case 2 shows the issue also reproduces on a plain table without either feature (at MV creation time).

### What You Expected?

1. A query with the same shape as a FINISHED sync MV (or a roll-up-compatible aggregate over its dimensions) should be transparently rewritten to the MV index; at minimum `EXPLAIN` should show the MV index selected instead of the base table.
2. Creating a simple aggregate sync MV over a plain DUPLICATE KEY table should succeed, or fail with a clear error message.

### How to Reproduce?

Cluster: Doris 4.1.3, 1 FE / 2 BE, default session variables except where noted.

Case 1 (rewrite never selects a FINISHED sync MV): run the DDL + MV + EXPLAIN from "What's Wrong". The base table in our cluster has ~20M rows loaded via Routine Load; `SHOW ALTER TABLE MATERIALIZED VIEW` shows FINISHED, but EXPLAIN always scans the base table.

Case 2 (minimal MV creation failure), fully self-contained:

```sql
CREATE TABLE tmp_mv_probe (k1 VARCHAR(64) NOT NULL, k2 INT NOT NULL, v BIGINT NOT NULL)
DUPLICATE KEY(k1, k2)
DISTRIBUTED BY HASH(k1) BUCKETS 1
PROPERTIES('replication_num'='2');

CREATE MATERIALIZED VIEW mv_probe AS
SELECT k1, k2, MAX(v) AS max_v FROM tmp_mv_probe GROUP BY k1, k2;
-- ERROR 1105 (HY000): errCode = 2, detailMessage = Duplicate column name 'k1'
```

### Anything Else?

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

Start with the self-contained tmp_mv_probe DDL and then reproduce Case 1 using EXPLAIN, EXPLAIN VERBOSE, and SHOW ALTER TABLE MATERIALIZED VIEW. Trace why the FINISHED sync MV is not selected and why the simple aggregate MV reports a duplicate column; done means both cases either work as expected or return a clear, verified explanation.

Written by the indexing model from the issue text.