ci: avoid moving prerelease tag and skip irrelevant CodeQL scans

[CaseyLabs]

Overview

1. The "moving" prerelease tag (used to keep the prerelease notes up to date) was causing the following issue on local developer git pulls:

❯ git pull
From github.com:GoMudEngine/GoMud
! [rejected] prerelease -> prerelease  (would clobber existing tag)

2. CodeQL was running Go and Javascript code analysis on each PR, even if no relevant changes had been made.

Changes

• replace the force-moved prerelease tag with generated immutable prerelease tags
• publish the new rolling prerelease, then delete older rolling prerelease releases/tags
• update release docs and user-facing guide wording for the rolling prerelease entry
• split CodeQL into Go and JavaScript/TypeScript jobs behind a changed-path detector so unrelated PRs skip irrelevant language scans without workflow-level path filters
• run JavaScript/TypeScript CodeQL for first-party HTML changes while preserving vendored web asset exclusions