Restore epsilon in block collision checks or add a config toggle to fix AI pathfinding regressions

[TKostofan]

Is your feature request related to a problem?

Yes. Starting from build #116 (commit 1f1406f), there is a significant regression in how automated entities (bots/AI) interact with terrain. By removing the epsilon value for whole-block collision checks, the server now enforces "pixel-perfect" collisions.

When an AI entity (like a Mineflayer bot) moves flush against a block to jump, the server rejects the upward movement because the hitbox is perfectly aligned with the block's edge. This causes bots to get stuck and "vibrate" in place instead of jumping. This was perfectly working in builds #112-#115.

Describe the solution you'd like.

I would like to see the "epsilon padding" restored for collision checks with solid blocks, or at least a configuration option in paper-world-defaults.yml (e.g., collisions.use-legacy-epsilon) to restore the previous behavior. This would allow AI entities to maintain enough "gap" from blocks to perform vertical movements (jumping/climbing) without being blocked by the new strict collision logic.

Describe alternatives you've considered.

1. Reverting to build 1.8.8 bug (invalidconfigurationexception) #115 (Current workaround).
2. Attempting to "hardcode" movement offsets in the bot's framework (e.g., forcing the bot to move back before every jump), which is inefficient and breaks natural movement fluidness.
3. Modifying max-entity-collisions in Paper config, which does not resolve the core mathematical collision issue introduced in build Banner waving workaround #116.

Other

The commit message for 1f1406f explicitly stated: "I'm sure this is going to cause some collision problem but we will cross that bridge when it happens." As a developer of an AI framework for Minecraft, I can confirm that this "bridge" has been reached. Strict vanilla collisions are great for players but break many existing AI pathfinding implementations that rely on the tiny epsilon gap to navigate slopes and stairs.

[SeasonPhan]

for the love of god makes this a configurable entry
it took me 2 days of searching around wondering why the bot didnt jump properly