fix: add .compaction-queue to handle in-mid compaction crash

[dkharms]

Description

Compaction's substitute-and-delete of stale fractions isn't atomic, so a crash mid-compaction could leave source fractions behind and produce duplicates on restart.

This adds a .compaction-queue file recording the participating fractions, which is written before merging and used on startup to clean up any leftover sources from an interrupted compaction.

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[dkharms]

@seqbenchbot up main bulk

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@seqbenchbot down 8eedacf8

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Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	68.14	66.54	-2.34%	39.10	28.75	-26.46%	55.00	59.00	+7.27%	163.00	119.00	-26.99%	223.00	194.00	-13.00%	92689.00	92790.00	+0.11%

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[dkharms]

@seqbenchbot up main bulk

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Identificator for your ongoing benchmark - 1c283919.

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@seqbenchbot down 1c283919

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Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	89.78	83.67	-6.80%	58.54	42.06	-28.15%	67.00	70.00	+4.48%	225.00	167.00	-25.78%	298.00	252.00	-15.44%	1540251.00	1540362.00	+0.01%

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[dkharms]

@seqbenchbot up main bulk

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Identificator for your ongoing benchmark - 36d0de9f.

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@seqbenchbot down 36d0de9f

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Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	67.39	62.57	-7.16%	43.57	29.77	-31.69%	51.00	53.00	+3.92%	173.00	118.00	-31.79%	234.00	193.00	-17.52%	716648.00	716757.00	+0.02%

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[dkharms]

@seqbenchbot up main mixed

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Identificator for your ongoing benchmark - 29d571ac.

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[dkharms]

@seqbenchbot down 29d571ac

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Nice, @dkharms <(-^,^-)=b!

The benchmark with identificator 29d571ac was finished.
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Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	48.99	50.87	+3.84%	11.90	13.74	+15.47%	47.00	48.00	+2.13%	70.00	76.00	+8.57%	93.00	102.00	+9.68%	45658.00	45585.00	-0.16%
service:payment-backend-eu AND k8s_namespace:prod AND level:[0 to 3] AND ( message:'failed' OR message:'timeout' )	warm	53.72	58.03	+8.02%	20.62	24.77	+20.15%	45.00	48.00	+6.67%	97.00	113.00	+16.49%	117.00	139.50	+19.23%	9615.00	9596.00	-0.20%

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