Fix typos in comments

[leopardracer]

This PR fixes minor typos in comments across several files:

• ReputationMiningCycleBinarySearch.sol: Fixed "challenge" spelling in comment
• ReputationMiningCycleRespond.sol: Fixed "everything" spelling in comment
• ReputationMiner.js: Fixed hyphenation in "user-specific" comment

These changes only affect comments and have no functional impact on the code.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}