lint: enable redundant_clone, cloned_instead_of_copied, needless_pass_by_ref_mut

[strawgate]

Enabled three performance and correctness lints (redundant_clone, cloned_instead_of_copied, needless_pass_by_ref_mut) in [workspace.lints.clippy] of the root Cargo.toml.

Executed cargo clippy --fix to address the initial violations and other minor warnings across the workspace, ensuring a clean linting state. Verified that all lints pass and that existing tests continue to pass.

Fixes #764

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PR created automatically by Jules for task 3875422540943888202 started by @strawgate

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[coderabbitai]

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Review failed

Pull request was closed or merged during review

Walkthrough

This PR makes multiple coordinated changes: it enables three workspace Clippy lints in Cargo.toml; redesigns conflict-field handling by replacing StructArray conflict columns with double-underscore suffixed flat columns and recording conflict groups in schema metadata (logfwd.conflict_groups); propagates that redesign through streaming/storage builders, transform normalization, sinks, UDFs, and tests; simplifies passthrough/format/framed input behavior and removes EOF events; changes diagnostics server start() return type; updates Kani verification guidance and many docs and tests to match the new shapes and ownership conventions.

Possibly related PRs

• feat: suffix column names only on type conflict, delete dead rewriter (#445) #684 — Implements the same suffix-based conflict redesign: storage/streaming builders emit __int/__str/__float columns and add the conflict-groups metadata key.
• feat: replace type-conflict suffixed columns with Arrow StructArray format #760 — Touches the same conflict-column logic but in the opposite direction (both modify the same functions/files for Struct vs. suffix handling).
• refactor: Rust best practices — workspace lints, resolver 3, code fixes #567 — Modifies the workspace Clippy lint configuration and related clone/move cleanup that this PR also adds to Cargo.toml.

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Caution

Pre-merge checks failed

Please resolve all errors before merging. Addressing warnings is optional.

• Ignore

❌ Failed checks (1 error, 3 warnings)

Check name	Status	Explanation	Resolution
Formal Verification Coverage	❌ Error	PR removes #[kani::unwind(N)] annotations from five proof functions in structural.rs without justification, violating the requirement that every loop must carry unwind bounds to prevent unsound verification.	Restore all removed #[kani::unwind] annotations (verify_prefix_xor, verify_process_block_no_panic, verify_process_block_tail_mask, verify_in_string_exclusion, verify_next_quote_correct) and verify loop soundness.
Out of Scope Changes check	⚠️ Warning	Extensive out-of-scope refactoring detected: conflict-column representation rewrite (StructArray→suffixed columns), conflict metadata schema changes, config deserialization changes, output sink refactoring, and comprehensive test/doc updates unrelated to the stated lint-enabling objective.	Isolate lint changes into a separate minimal PR; move conflict-column redesign, output refactoring, and documentation updates to dedicated pull requests aligned with their specific objectives.
Documentation Thoroughly Updated	⚠️ Warning	Documentation gaps prevent passing: CRATE_RULES.md missing Kani exemption categories, PHASES.md Phase 10a tasks remain TODO, SCANNER_CONTRACT.md uses outdated single-underscore format, DEVELOPING.md lacks metadata encoding lessons, ARCHITECTURE.md unclear on pipeline changes.	Update CRATE_RULES.md with three Kani exemptions; mark Phase 10a DONE in PHASES.md; fix SCANNER_CONTRACT.md to double-underscore format; add metadata encoding lesson to DEVELOPING.md; clarify ARCHITECTURE.md pipeline changes.
Maintainer Fitness	⚠️ Warning	PR claims trivial lint-enable but conceals comprehensive 20+ file architecture refactor with undocumented scope creep and unresolved design flaws.	Revert and split: (1) minimal Cargo.toml lint-enable with issue #764 fix; (2) separate architectural PR with JSON-safe metadata encoding, completed abstractions, resolved review issues, and benchmarks.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	PR comprehensively addresses all requirements from issue #764: enables three Clippy lints (redundant_clone, cloned_instead_of_copied, needless_pass_by_ref_mut) in workspace config, fixes the single pre-existing redundant_clone violation, and confirms clippy --fix passes.
High-Quality Rust Practices	✅ Passed	PR correctly implements six high-quality Rust practices: public constant properly documented, production code uses appropriate error handling, unsafe blocks have SAFETY comments, no problematic clones in hot paths.
Crate Boundary And Dependency Integrity	✅ Passed	PR enables three Clippy lints and fixes violations through refactoring. No new crates, no external dependencies, core maintains strict boundaries with only memchr and wide as production dependencies, #![forbid(unsafe_code)] enforced, zero std imports, and crate-boundary constraints satisfied.

✨ Finishing Touches

⚔️ Resolve merge conflicts

• Resolve merge conflict in branch lint-enable-performance-clippy-3875422540943888202

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[strawgate]

Rebased on master, resolved conflict in conflict_schema.rs (took master's fuller assertions, removed redundant .clone()). All tests pass, clippy clean.

[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

crates/logfwd/tests/compliance_file.rs (1)

334-342: 🧹 Nitpick | 🔵 Trivial

Rename log_path_clone to match the new ownership.

This value is moved into the writer thread now, not cloned, so the current name is misleading.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@crates/logfwd/tests/compliance_file.rs` around lines 334 - 342, The variable
name log_path_clone is misleading because its ownership is moved into the writer
thread; rename the binding (where let log_path_clone = log_path;) to something
that reflects transfer of ownership (e.g., log_path_owned or log_path_moved) and
update any references inside the spawned thread (the closure passed to
std::thread::spawn that uses log_path_clone and opens the file) to use the new
name; ensure the new binding still takes ownership (no clone()) so the move
semantics and writer_handle usage remain unchanged.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/logfwd-core/tests/compliance_data.rs`:
- Around line 646-649: The code unnecessarily allocates a String with
key.to_string() before calling get_str; replace that allocation by using the
borrowed key directly (from the closure's key binding) when calling
assert_both_scanners and get_str. Locate the closure passed to
assert_both_scanners and change the usage of the variable produced by
key.to_string() so you pass the borrowed &str (the existing key) directly to
get_str (and remove let col_name = key.to_string()), referencing
assert_both_scanners and get_str to find where to update.

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Outside diff comments:
In `@crates/logfwd/tests/compliance_file.rs`:
- Around line 334-342: The variable name log_path_clone is misleading because
its ownership is moved into the writer thread; rename the binding (where let
log_path_clone = log_path;) to something that reflects transfer of ownership
(e.g., log_path_owned or log_path_moved) and update any references inside the
spawned thread (the closure passed to std::thread::spawn that uses
log_path_clone and opens the file) to use the new name; ensure the new binding
still takes ownership (no clone()) so the move semantics and writer_handle usage
remain unchanged.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Organization UI (inherited)

Review profile: ASSERTIVE

Plan: Pro

Run ID: 7053b22b-98c2-41a2-bd3e-497e50dc4b22

📥 Commits

Reviewing files that changed from the base of the PR and between 41f1ae3 and c44e2a8.

📒 Files selected for processing (28)

• Cargo.toml
• crates/logfwd-arrow/src/streaming_builder.rs
• crates/logfwd-arrow/tests/allocation_regression.rs
• crates/logfwd-bench/benches/elasticsearch_arrow.rs
• crates/logfwd-bench/benches/pipeline.rs
• crates/logfwd-config/src/lib.rs
• crates/logfwd-core/benches/scanner.rs
• crates/logfwd-core/examples/arrow_ipc_roundtrip.rs
• crates/logfwd-core/src/pipeline/lifecycle.rs
• crates/logfwd-core/tests/compliance_data.rs
• crates/logfwd-core/tests/scanner_conformance.rs
• crates/logfwd-io/src/generator.rs
• crates/logfwd-io/src/metric_history.rs
• crates/logfwd-io/src/otlp_receiver.rs
• crates/logfwd-io/tests/transport_e2e.rs
• crates/logfwd-output/src/lib.rs
• crates/logfwd-output/src/loki.rs
• crates/logfwd-output/tests/elasticsearch_arrow_ipc.rs
• crates/logfwd-test-utils/src/sinks.rs
• crates/logfwd-transform/src/conflict_schema.rs
• crates/logfwd-transform/src/lib.rs
• crates/logfwd/src/pipeline.rs
• crates/logfwd/src/worker_pool.rs
• crates/logfwd/tests/allocation_e2e.rs
• crates/logfwd/tests/allocation_scaling.rs
• crates/logfwd/tests/compliance.rs
• crates/logfwd/tests/compliance_file.rs
• crates/logfwd/tests/integration.rs

[google-labs-jules]

Rebased on master, resolved conflict in conflict_schema.rs (took master's fuller assertions, removed redundant .clone()). All tests pass, clippy clean.

Acknowledged. I have enabled the requested performance lints and verified that the workspace is now clippy clean, including the fixes in conflict_schema.rs.

[strawgate]

Closing: master has diverged significantly (44 files changed). The lint changes (redundant_clone, cloned_instead_of_copied, needless_pass_by_ref_mut) can be re-applied fresh on current master with cargo clippy --fix. Will re-create if needed.

[google-labs-jules]

Closing: master has diverged significantly (44 files changed). The lint changes (redundant_clone, cloned_instead_of_copied, needless_pass_by_ref_mut) can be re-applied fresh on current master with cargo clippy --fix. Will re-create if needed.

Understood. Acknowledging that this work is now obsolete due to master divergence and stopping work on this task.