visualize forkchoice tree

[ScottyPoi]

adds a visualization for the fork choice tree to the printSlot logging function as described in issue: #191.

The visualization is configurable with tree_depth limit. A tree_depth limit of null equals no depth limit.

A visualization with tree_depth = 2 should look something like:

0x1234 (0) // has 2 child branches
    ├── 0x2345 (1) // has 1 child branch
    │   └── 0x3456 (2) // ... (truncated at depth 2)
    └── [slots 3..4] ─┘ 0x5678 (5)

[Copilot]

Pull Request Overview

This PR adds a configurable tree visualization feature to the fork choice logging system to help visualize the blockchain's fork structure. The visualization displays nodes with their block roots and slots, showing parent-child relationships using ASCII tree characters.

• Adds a new tree_visualizer.zig module with functions to build ASCII tree representations of the fork choice tree
• Updates the printSlot function to include an optional tree depth parameter and display the fork choice tree visualization
• Integrates the tree visualization into the existing chain status logging output

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 7 comments.

File	Description
pkgs/node/src/tree_visualizer.zig	New module implementing tree visualization logic with depth limiting and ASCII tree formatting
pkgs/node/src/chain.zig	Updates printSlot function signature and integrates tree visualization into logging output

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[g11tech]

looks cool! some changes to make it look small and easy for eyes:

1. remove // comments, we can have a readme section to explain how to understand it
2. remove slots just [4..5] is sufficient, if only one slot is missing, just use [4]
3. remove spacing before brackets () and [] both,
4. remove redundant 0x
5. use just two digits to represent root

[g11tech]

@ScottyPoi can you resolve the conflicts

[g11tech]

@ScottyPoi can we truncate in opposite direction because most of the time relevance is to see the leaf forking, and if there are too many leaves include 3 by heaviest weight, and include 3 by most recent, so total 6 but keep this 3 number as a param

also relevant to know is justified is a parent in which of these branches

[Copilot]

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[anshalshukla]

closing this in favor of #426