fix: attach table does not carry the indexes of the original table

[KKould]

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Summary

when attaching a table, the Indexes in the TableMeta will be lost.

• Ngram Index
• Vector Index
• Inverted Index

after this pr:

show indexes

╭──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│  name  │   type  │  database │          table         │ original │                                 definition                                 │         created_on         │      updated_on     │
│ String │  String │   String  │    Nullable(String)    │  String  │                                   String                                   │          Timestamp         │ Nullable(Timestamp) │
├────────┼─────────┼───────────┼────────────────────────┼──────────┼────────────────────────────────────────────────────────────────────────────┼────────────────────────────┼─────────────────────┤
│ 'idx1' │ 'NGRAM' │ 'default' │ 'amazon_reviews_ngram' │ ''       │ 'amazon_reviews_ngram(review_body)bloom_size=\'2097152\' gram_size=\'10\'' │ 2025-08-01 08:09:19.133712 │ NULL                │
│ 'idx1' │ 'NGRAM' │ 'default' │ 'attach_tbl3'          │ ''       │ 'attach_tbl3(review_body)bloom_size=\'2097152\' gram_size=\'10\''          │ 2025-08-01 08:13:11.131164 │ NULL                │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
2 rows read in 0.144 sec. Processed 2 rows, 368 B (13.89 rows/s, 2.50 KiB/s)

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[bohutang]

@KKould Do all index types work with this PR? Concerned about specialized indexes like inverted indexes, virtual column indexes, and others.

[KKould]

@KKould Do all index types work with this PR? Concerned about specialized indexes like inverted indexes, virtual column indexes, and others.

In theory, as long as the indexes in TableMeta and the index files are stored on S3, this PR can solve it. Maybe I should add more tests to check the covered indexes.