feat: add benchmark results for TurboPuffer

[jamesgao-jpg]

Summary

• Add --region CLI parameter (required) for region-based API routing, making --api-base-url an optional override for private networking
• Fix SDK compatibility: rename write(columns=...) to write(upsert_columns=...) per current TurboPuffer SDK
• Fix pickle error: defer tpuf.Turbopuffer client creation to init() to avoid serialization errors with ProcessPoolExecutor(spawn)
• Fix recall comparison: cast search result IDs to int for ground truth matching
• Fix docstring: correct copy-paste references to Pinecone/Milvus
• Add benchmark results: consolidated TurboPuffer filter performance results (20 entries) and streaming benchmark entries (500/1000 rows/s)

Changes

Client fixes (backend/clients/turbopuffer/)

File	Change
cli.py	Add --region option (required); make --api-base-url optional with no default
config.py	Add region field; make api_base_url optional (None default)
turbopuffer.py	Defer client creation to _create_client() called in init() (fixes pickle); pass region to SDK; use upsert_columns instead of columns; cast result IDs to int; fix docstring

Benchmark results

File	Change
results/TurboPuffer/result_20260331_standard_2025_turbopuffer.json	Consolidated results from 22 individual TurboPuffer benchmark runs
results/leaderboard_v2.json	+20 TurboPuffer filter performance entries
results/leaderboard_v2_streaming.json	+2 TurboPuffer streaming benchmark entries (500/1000 rows/s)

Test plan

• Run TurboPuffer benchmarks with --region aws-us-east-1 and verify client connects correctly
• Verify --api-base-url override still works when provided
• Confirm search recall scores match expected values (ID type casting fix)
• Verify no pickle errors when running with multiprocess executor

[liliu-z]

/lgtm
/approve

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: jamesgao-jpg, liliu-z
To complete the pull request process, please assign xuanyang-cn after the PR has been reviewed.
You can assign the PR to them by writing /assign @xuanyang-cn in a comment when ready.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment