Feature/cmdline overrides

[beesyst]

Summary
Added support for overriding config options via command-line flags, as discussed in #5098. Now options like --hugetlbfs.max_page_size huge work as expected.

Scope

• Affected file: src/app/shared/boot/fd_boot.c

Reason
Implements feature requested in issue to allow easier configuration overrides from the CLI.

Testing
Full validator run was not possible due to resource limits (my dev machine couldn’t handle the full launch),
BUT:

• Wrote a minimal local test to call apply_cmdline_overrides() directly with sample argv/argc.
• Output confirmed override logic works: hugetlbfs.max_page_size = huge
• Manual code review also confirmed behavior.

[mmcgee-jump]

Not sure why there are 3 unrelated commits in this PR. But please follow FD style when making changes, and resubmit.

[beesyst]

Not sure why there are 3 unrelated commits in this PR. But please follow FD style when making changes, and resubmit.

Yep, for some reason, one commit from the previous issue got into #5526. And two extra files along with it. I wanted to delete them, but you already closed it. Created a new one.

[ripatel-fd]

Hi @beesyst, thanks again for your contribution. I suggest we first chat about which issues can be fixed at the moment, which ones we have bandwidth to review, and how to approach them, so we don't waste your time. We haven't accepted external contributions except for typo fixes so far (mostly because not many people submit changes). So, we don't have great issue descriptions. For this PR for example, I was hoping for a more general approach that hooks into the TOML config loader, instead of hardcoding individual config entries. We are also a bit cautious with AI generated code, since it is quick to generate, but it takes a long time to review for errors.