WIP (fuzz): investigate under constrained found in merkle sum tree chip

[zeroqn]

Describe the bug
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main.rs
replace
main.rs from summa-analysis

To Reproduce
Steps to reproduce the behavior:

cargo run
4 (mode 4)
1 (verify the circuit for a specific public input)
99 (I-0-0 next left hash)
10 (I-1-0 next right hash)
1 (I-2-0 swap bit)

Expected behavior
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sat

Additional context
Add any other context about the problem here.

MST chip is wrapped in FuzzMSTChip

halo2-analyzer found 5 unconstrained cells

unconstrained cell in "assign nodes hashes per merkle tree level" region: Column { index: 1, column_type: Advice } (rotation: 0) -- very likely a bug.
unconstrained cell in "assign nodes hashes per merkle tree level" region: Column { index: 1, column_type: Advice } (rotation: 0) -- very likely a bug.
unconstrained cell in "assign nodes hashes per merkle tree level" region: Column { index: 0, column_type: Advice } (rotation: 0) -- very likely a bug.
unconstrained cell in "assign nodes hashes per merkle tree level" region: Column { index: 2, column_type: Advice } (rotation: 0) -- very likely a bug.
unconstrained cell in "assign nodes hashes per merkle tree level" region: Column { index: 0, column_type: Advice } (rotation: 0) -- very likely a bug.