Fix brute force Rust index dataset lifetime

[yan-zaretskiy]

• Keep the consumed ManagedTensor alive inside brute_force::Index so the C++ side's dataset view does not point at freed device memory.
• Remove the flaky test marker dependency.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 611f55ee-da79-4825-9a9b-b49103d50c84

📥 Commits

Reviewing files that changed from the base of the PR and between 86b9038 and fe13522.

📒 Files selected for processing (2)

• rust/cuvs/Cargo.toml
• rust/cuvs/src/brute_force.rs

💤 Files with no reviewable changes (1)

• rust/cuvs/Cargo.toml

---

📝 Walkthrough

Summary by CodeRabbit

Bug Fixes

• Fixed dataset memory management in brute-force index operations to prevent potential crashes
• Ensured indexed datasets remain available for the lifetime of index operations

Tests

• Stabilized previously flaky brute-force search tests for more reliable test results

Walkthrough

The PR fixes a dataset lifetime issue in the brute-force index by storing the indexed dataset within the Index struct and removes the flaky test infrastructure by converting a test from #[flaky] to a standard test.

Changes

Index Lifetime Management and Flaky Test Removal

Layer / File(s)	Summary
Index struct refactoring and lifetime management rust/cuvs/src/brute_force.rs	Index struct changes from a tuple struct to a named struct with inner field for the C++ handle and _dataset field storing an optional ManagedTensor. The build() method assigns the built index to inner and persists the input dataset in _dataset, whereas previously the dataset was dropped after build. Methods new(), search(), and Drop are updated to use the inner field instead of tuple-struct field access.
Remove flaky test infrastructure rust/cuvs/Cargo.toml, rust/cuvs/src/brute_force.rs	mark-flaky-tests = "1" dependency is removed from Cargo.toml. The mark_flaky_tests::flaky import is removed from the test module, and the L2 search test annotation is changed from #[flaky] to #[test].

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: fixing the lifetime management of the dataset in the brute force Rust index.
Description check	✅ Passed	The description accurately relates to the changeset, explaining both the dataset lifetime fix and the removal of the flaky test marker dependency.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[cjnolet]

/merge