fix(hadoop): use codec-aware metadata filenames

[fallintoplace]

Summary

• write Hadoop metadata files with suffixes that match the configured metadata compression codec
• load the actual discovered metadata file path instead of reconstructing an uncompressed-looking path
• teach Hadoop metadata discovery to recognize plain, gzip, and zstd metadata files consistently

Why

Hadoop currently always writes metadata to vN.metadata.json even when write.metadata.compression-codec requests gzip or zstd. The table metadata reader infers decompression from the filename suffix, so compressed bytes behind a plain .metadata.json path can fail to reload.

Using codec-aware filenames on write and carrying the discovered metadata path through LoadTable keeps create, commit, and reload consistent for plain, gzip, and zstd metadata.

Testing

• go test ./catalog/hadoop -run 'TestHadoopCatalogTestSuite/(TestMetadataFilePathForCompression|TestVersionPatternMatches|TestIsTableDirWithZstdMetadata|TestFindVersionGzipOnlyWithHint|TestFindVersionMixedGzipAndPlain|TestFindVersionZstdOnlyWithHint|TestFindVersionMixedZstdAndPlain|TestCreateTableGzipMetadata|TestCreateTableZstdMetadata|TestCommitTableGzipMetadata|TestCommitTableZstdMetadata)$' -count=1
• go test ./catalog/hadoop -count=1
• go test ./catalog/... -count=1
• go test ./... -run '^$' -count=1
• go run github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.11.4 run --timeout=10m ./catalog/hadoop/...
• git diff --check

[tanmayrauth]

Looks good — write suffix now matches the read-path codec inference in table.go, and the create→load / commit→load round-trip tests cover both gzip and zstd. One tiny nit.

[tanmayrauth]

After this change metadataFilePath no longer has a production caller, CreateTable/CommitTable/LoadTable all go through metadataFilePathForCompression / findMetadataLocation now. It's still referenced from the tests so it's not dead, but might be worth either keeping it explicitly as a test-only helper or pointing those tests at the new helper to avoid drift.

[fallintoplace]

This seems to be a valid comment, I will amend the PR. Have a nice weekend.