ci: reject implicit engine buffer allocation

[gatesn]

Summary

Reject implicit buffer allocation in engine code.

Changes

• Add a check for implicit constructors in allocator-aware paths.
• Run the check in Rust lint CI.

[codspeed-hq]

Merging this PR will degrade performance by 0.58%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 94 improved benchmarks
❌ 158 regressed benchmarks
✅ 1917 untouched benchmarks
⏩ 106 skipped benchmarks¹
🗄️ 4 archived benchmarks run²

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	decompress[datetime_for_bp]	218.2 µs	404.6 µs	-46.08%
❌	Simulation	new_bp_prim_test_between[i64, 2048]	87.3 µs	155.7 µs	-43.93%
❌	Simulation	new_alp_prim_test_between[f64, 2048]	104.8 µs	172.3 µs	-39.16%
❌	Simulation	decompress_rd[f64, (2000, 0.1)]	118.7 µs	186.9 µs	-36.49%
❌	Simulation	decompress_rd[f64, (2000, 0.0)]	118.7 µs	186.8 µs	-36.47%
❌	Simulation	decompress_rd[f64, (2000, 0.01)]	118.8 µs	186.9 µs	-36.46%
❌	Simulation	decompress[alp_for_bp_f64]	146.7 µs	225 µs	-34.81%
❌	Simulation	alp_rd_decompress_f64	167.2 µs	234.9 µs	-28.81%
❌	Simulation	new_bp_prim_test_between[i64, 16384]	169.2 µs	237.2 µs	-28.68%
❌	Simulation	new_alp_prim_test_between[f64, 16384]	191.2 µs	259.6 µs	-26.36%
❌	Simulation	compare[1]	205.2 µs	273.5 µs	-24.96%
❌	Simulation	compare[1]	208.3 µs	275.9 µs	-24.51%
❌	Simulation	compact_sliced[(2048, 10)]	201.1 µs	266.1 µs	-24.43%
❌	Simulation	compare[2]	211.7 µs	279.8 µs	-24.33%
❌	Simulation	compare[2]	215 µs	283 µs	-24.02%
❌	Simulation	compact_sliced[(1024, 10)]	103.1 µs	135.6 µs	-23.93%
❌	Simulation	compare[3]	219.1 µs	287.1 µs	-23.67%
❌	Simulation	compare[3]	222.2 µs	290.3 µs	-23.47%
❌	Simulation	compare[4]	224.6 µs	292.6 µs	-23.24%
❌	Simulation	compare[4]	228 µs	295.8 µs	-22.93%
...	...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing ngates/buffer-allocator-enforce (b09ec24) with ngates/buffer-allocator-execution (eecf43a)³}

Footnotes

1. 106 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. 4 benchmarks were run, but are now archived. If they were deleted in another branch, consider rebasing to remove them from the report. Instead if they were added back, click here to restore them. ↩

3. No successful run was found on ngates/buffer-allocator-execution (187bae1) during the generation of this report, so adf1ccb was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩