Boost: Minify codebase improvements

### Impacted plugin

Boost

### Quick summary

There are quite a few todo items left over from when Page Optimize was migrated to Minify.

### Steps to reproduce

n/a

### A clear and concise description of what you expected to happen.

_No response_

### What actually happened

_No response_

### Impact

One

### Available workarounds?

There is no user impact

### Platform (Simple and/or Atomic)

Simple

### Logs or notes

* [ ] Was in Page Optimize prior to moving to Minify;
https://github.com/Automattic/jetpack/blob/5ad11d79e238d20ebd17f863d51cf887d5bc4351/projects/plugins/boost/app/modules/optimizations/minify/Minify.php#L13
* [ ] https://github.com/Automattic/jetpack/blob/5ad11d79e238d20ebd17f863d51cf887d5bc4351/projects/plugins/boost/app/modules/optimizations/minify/class-css.php#L26
* [ ] https://github.com/Automattic/jetpack/blob/5ad11d79e238d20ebd17f863d51cf887d5bc4351/projects/plugins/boost/app/modules/optimizations/minify/class-js.php#L26
* [ ] https://github.com/Automattic/jetpack/blob/5ad11d79e238d20ebd17f863d51cf887d5bc4351/projects/plugins/boost/app/modules/optimizations/minify/functions-helpers.php#L8
* [ ] https://github.com/Automattic/jetpack/blob/a940835b6d1b91b58cab8781c907a18dc1785107/projects/plugins/boost/wp-js-data-sync.php#L145

Start by reviewing the TODO references in projects/plugins/boost/app/modules/optimizations/minify/Minify.php, class-css.php, class-js.php, functions-helpers.php, and wp-js-data-sync.php. Compare the Minify migration with the linked Page Optimize history to identify the remaining work. The issue does not define specific completion criteria or name tests, so the TODO scope should be clarified before implementation.

Written by the indexing model from the issue text.