perf: implement bitpack encoding for LID and MID blocks (draft, work in progress)

[cheb0]

Description

Fixes #312

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[cheb0]

@seqbenchbot up main search-logbench

[seqbenchbot]

Nice, @cheb0 <(-^,^-)=b!

Your request was successfully served.
Identificator for your ongoing benchmark - acee5e23.

Here is a list of helpful links:

• Take a look at [Grafana](https://comparison.seqbench.ozon.dev/grafana/d/1f4558f2-1bd6-4034-b6db-6607726e78df?var-scenario=search-logbench&var-container=seqbench-seqdb-acee5e23-baseline&var-container=seqbench-seqdb-acee5e23-comparison&from=seqbench-seqdb-acee5e23-comparison%!(EXTRA string=2026-02-06T14:06:53.520Z)) dashboard;
• Live-tailing logs are also available;

Have a great time!

[codecov-commenter]

Codecov Report

❌ Patch coverage is 73.33333% with 72 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.60%. Comparing base (03387c3) to head (3accfd6).

Files with missing lines	Patch %	Lines
frac/sealed/lids/block2.go	0.00%	44 Missing ⚠️
packer/bitpack_packer.go	74.76%	16 Missing and 11 partials ⚠️
frac/sealed/seqids/loader.go	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #328      +/-   ##
==========================================
+ Coverage   71.40%   71.60%   +0.20%     
==========================================
  Files         206      208       +2     
  Lines       15057    15295     +238     
==========================================
+ Hits        10751    10952     +201     
- Misses       3523     3547      +24     
- Partials      783      796      +13     

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[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
And/size=1000-4	03387c	228a3d
	4.29 ns/op	5.21 ns/op	1.21	🔴
Block_Pack-4	------	228a3d
	NaN B/op	1144.00 B/op	NaN	🔴
	NaN allocs/op	8.00 allocs/op	NaN	🔴
	NaN ns/op	1478.00 ns/op	NaN	🔴
Block_Unpack-4	------	228a3d
	NaN B/op	96260.00 B/op	NaN	🔴
	NaN allocs/op	2.00 allocs/op	NaN	🔴
	NaN ns/op	73415.00 ns/op	NaN	🔴
FindSequence_Random/medium-4	03387c	228a3d
	11010.51 MB/s	9478.32 MB/s	0.86	🔴
	93.34 ns/op	108.00 ns/op	1.16	🔴
FindSequence_Random/small-4	03387c	228a3d
	6427.67 MB/s	5110.10 MB/s	0.80	🔴
	40.85 ns/op	50.10 ns/op	1.23	🔴
ProcessDocuments-4	03387c	228a3d
	29061.00 B/op	32645.00 B/op	1.12	🔴
	101.50 MB/s	91.92 MB/s	0.91	🔴
Sealing_NoSort-4	03387c	228a3d
	24735232.00 B/op	70504464.00 B/op	2.85	🔴
	5899.00 allocs/op	7128.00 allocs/op	1.21	🔴
Sealing_WithSort-4	03387c	228a3d
	41258232.00 B/op	86940672.00 B/op	2.11	🔴
	5980.00 allocs/op	7211.00 allocs/op	1.21	🔴

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
AggDeep/size=10000-4	03387c	f02de4
	45145.00 ns/op	56064.00 ns/op	1.24	🔴
AggDeep/size=1000000-4	03387c	f02de4
	4554859.00 ns/op	5743173.00 ns/op	1.26	🔴
And/size=1000-4	03387c	f02de4
	4.29 ns/op	4.99 ns/op	1.16	🔴
Block_Pack-4	------	f02de4
	NaN B/op	1144.00 B/op	NaN	🔴
	NaN allocs/op	8.00 allocs/op	NaN	🔴
	NaN ns/op	1468.00 ns/op	NaN	🔴
Block_Unpack-4	------	f02de4
	NaN B/op	96260.00 B/op	NaN	🔴
	NaN allocs/op	2.00 allocs/op	NaN	🔴
	NaN ns/op	84777.00 ns/op	NaN	🔴
FindSequence_Random/small-4	03387c	f02de4
	6427.67 MB/s	5639.08 MB/s	0.88	🔴
	40.85 ns/op	45.40 ns/op	1.11	🔴
Sealing_NoSort-4	03387c	f02de4
	24735232.00 B/op	70506000.00 B/op	2.85	🔴
	5899.00 allocs/op	7136.00 allocs/op	1.21	🔴
Sealing_WithSort-4	03387c	f02de4
	41258232.00 B/op	86941072.00 B/op	2.11	🔴
	5980.00 allocs/op	7214.00 allocs/op	1.21	🔴