feat(dataset): add contributor metadata storage and API

[xuang7]

What changes were proposed in this PR?

This PR adds contributor metadata to datasets so that dataset authors and other contributors can be properly acknowledged. Each dataset can record a list of contributors, where each contributor has a name, a creator flag, and optional email, affiliation, and free-text comments fields.

Changes:

• Adds a new dataset_contributor table with a foreign key to dataset and cascade deletion in texera_ddl.sql, along with the incremental migration script sql/updates/30.sql and changelog entry 30.
• Updates file-service so that contributors are:
  • returned with the dataset detail response,
  • accepted during dataset creation, and
  • replaceable through a new POST /dataset/update/contributors endpoint (with did in the request body, matching the existing update/description and update/name endpoints), protected by the existing WRITE-access check.
• Validates that each contributor has a name, and that name, email, and affiliation do not exceed 256 characters.
• Models email, affiliation, and comments as optional in the API: omitted fields deserialize to null.

Currently, contributors are stored independently for each dataset. Cross-dataset contributor identity is left as a future extension. The UI will be added in a follow-up PR.

Any related issues, documentation, discussions?

Related to #6926

How was this PR tested?

7 ScalaTest cases were added, covering persisting contributors at dataset creation, replacing and clearing the list, validation failures (missing name, over-length fields), the WRITE-access check, and cascade deletion when the dataset is removed.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Claude Fable 5)

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @mengw15, @kunwp1, @Neilk1021
  You can notify them by mentioning @mengw15, @kunwp1, @Neilk1021 in a comment.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 90.90909% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.58%. Comparing base (348fa88) to head (990cb4f).

Files with missing lines	Patch %	Lines
...ache/texera/service/resource/DatasetResource.scala	90.90%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #6952   +/-   ##
=========================================
  Coverage     80.58%   80.58%           
- Complexity     3890     3891    +1     
=========================================
  Files          1162     1162           
  Lines         46264    46284   +20     
  Branches       5153     5155    +2     
=========================================
+ Hits          37280    37298   +18     
- Misses         7319     7320    +1     
- Partials       1665     1666    +1     

Flag	Coverage Δ		*Carryforward flag
access-control-service	70.00% <ø> (ø)
agent-service	77.42% <ø> (ø)		Carriedforward from 0f7a426
amber	75.59% <ø> (ø)
computing-unit-managing-service	20.49% <ø> (ø)
config-service	65.97% <ø> (ø)
file-service	67.74% <90.90%> (+0.93%)	⬆️
frontend	83.22% <ø> (ø)		Carriedforward from 0f7a426
notebook-migration-service	78.89% <ø> (ø)
pyamber	97.36% <ø> (ø)		Carriedforward from 0f7a426
workflow-compiling-service	26.31% <ø> (ø)

*This pull request uses carry forward flags. Click here to find out more.

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[github-actions]

⚠️ Benchmark changes need a look

🟢 2 better · 🔴 6 worse · ⚪ 7 noise (<±5%) · 0 without baseline

Compared against main 348fa88 benchmarked on this same runner, so the delta is largely free of cross-runner hardware noise. The "7d avg" column still reflects the gh-pages dashboard. Treat <±5% as noise unless repeated.

Dashboard · Run

	config	throughput	MB/s	latency	max Δ latest / 7d
🔴	bs=10 sw=10 sl=64	491	0.3	19,730/28,688/28,688 us	🔴 +11.0% / 🔴 +77.1%
🔴	bs=100 sw=10 sl=64	1,023	0.624	96,775/114,012/114,012 us	🟢 -19.2% / 🟢 -6.8%
🔴	bs=1000 sw=10 sl=64	1,162	0.709	851,445/998,626/998,626 us	🔴 +11.4% / 🟢 +17.1%

Baseline details

Latest main 348fa88 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	491 tuples/sec	531 tuples/sec	765.25 tuples/sec	-7.5%	-35.8%
bs=10 sw=10 sl=64	MB/s	0.3 MB/s	0.324 MB/s	0.467 MB/s	-7.4%	-35.8%
bs=10 sw=10 sl=64	p50	19,730 us	17,781 us	12,703 us	+11.0%	+55.3%
bs=10 sw=10 sl=64	p95	28,688 us	27,447 us	16,199 us	+4.5%	+77.1%
bs=10 sw=10 sl=64	p99	28,688 us	27,447 us	19,557 us	+4.5%	+46.7%
bs=100 sw=10 sl=64	throughput	1,023 tuples/sec	1,040 tuples/sec	965.22 tuples/sec	-1.6%	+6.0%
bs=100 sw=10 sl=64	MB/s	0.624 MB/s	0.635 MB/s	0.589 MB/s	-1.7%	+5.9%
bs=100 sw=10 sl=64	p50	96,775 us	91,655 us	103,830 us	+5.6%	-6.8%
bs=100 sw=10 sl=64	p95	114,012 us	141,053 us	110,778 us	-19.2%	+2.9%
bs=100 sw=10 sl=64	p99	114,012 us	141,053 us	118,713 us	-19.2%	-4.0%
bs=1000 sw=10 sl=64	throughput	1,162 tuples/sec	1,176 tuples/sec	992.33 tuples/sec	-1.2%	+17.1%
bs=1000 sw=10 sl=64	MB/s	0.709 MB/s	0.718 MB/s	0.606 MB/s	-1.3%	+17.1%
bs=1000 sw=10 sl=64	p50	851,445 us	849,865 us	1,016,959 us	+0.2%	-16.3%
bs=1000 sw=10 sl=64	p95	998,626 us	896,328 us	1,062,501 us	+11.4%	-6.0%
bs=1000 sw=10 sl=64	p99	998,626 us	896,328 us	1,082,611 us	+11.4%	-7.8%

Raw CSV

config_idx,batch_size,schema_width,string_len,num_batches,total_ms,total_tuples,total_bytes,tuples_per_sec,mb_per_sec,lat_p50_us,lat_p95_us,lat_p99_us
0,10,10,64,20,407.06,200,128000,491,0.300,19729.69,28688.22,28688.22
1,100,10,64,20,1955.49,2000,1280000,1023,0.624,96775.48,114012.34,114012.34
2,1000,10,64,20,17215.42,20000,12800000,1162,0.709,851445.15,998625.50,998625.50

[Copilot]

Pull request overview

This PR extends Texera’s dataset metadata support by introducing first-class dataset contributor records in the database and exposing them through the file-service dataset APIs, enabling proper attribution beyond the dataset owner.

Changes:

• Adds a new dataset_contributor table via DDL + incremental migration and registers it in the SQL changelog.
• Extends file-service dataset creation/detail responses to persist and return contributor metadata.
• Introduces a new endpoint to replace a dataset’s contributor list, with ScalaTest coverage for persistence, replacement, validation, and cascade deletion.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
sql/updates/29.sql	Adds incremental migration for the new dataset_contributor table.
sql/texera_ddl.sql	Updates baseline schema to include dataset_contributor.
sql/changelog.xml	Registers migration 29 in the changelog.
file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala	Implements contributor persistence/retrieval + new update endpoint.
file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala	Adds tests covering contributor lifecycle, validation, permissions, and cascade behavior.

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

Suppressed comments (3)

file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala:186

• getContributorsByDid returns a List[Contributor] but the query has no ORDER BY, so API responses may return contributors in nondeterministic order depending on query plan/vacuum. Since the API models this as a list, it should return a stable order (e.g., insertion order via cid).

    ctx
      .selectFrom(DATASET_CONTRIBUTOR)
      .where(DATASET_CONTRIBUTOR.DID.eq(did))
      .fetch()

file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala:588

• updateDatasetContributors treats a missing contributors field (None) as Nil, which will silently clear all contributors if a client accidentally sends { "did": ... }. For a dedicated "replace contributors" endpoint, it’s safer to require the field explicitly (clients can send an empty list to clear).

      DatasetResource.insertContributors(
        ctx,
        modificator.did,
        modificator.contributors.getOrElse(Nil)
      )

file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala:576

• This test is titled "reject contributor fields longer than 256 characters" but it only exercises the over-length name path. Since the implementation also validates email and affiliation, add cases for those fields so the length validation is fully covered.

    assertThrows[BadRequestException] {
      datasetResource.updateDatasetContributors(
        DatasetResource.DatasetContributorsModification(
          createdDataset.dataset.getDid,
          Some(

[mengw15]

LGTM