fix: validate filtered vote responses

[ShiroKSH]

Summary

• restrict filtered ULX votes to the players that were sent the vote
• shorten admin approval votes from 30000 seconds to 30 seconds
• skip the final votekick if the target left during approval

Why

Filtered votes are used for admin approval after successful votemap, votekick, and voteban votes. The server only sent those votes to the approving admin, but any client could still run ulx_vote 1 manually and have the response counted.

The approval timeout also used 30000, which is interpreted as seconds and could block new votes for over eight hours.

Checks

• git diff --check
• manual review of public vote and filtered approval call sites

[ShiroKSH]

@Nayruden - could you take a look at the filtered vote-response validation in this PR when you have a chance, or route it to the right reviewer? I can make any requested changes or add tests. Thanks!