alt: in-house JSONC patcher instead of comment-json

[jycouet]

@manuel3108 #1381 adds ~16% to the sv-utils bundle (+44 KB gzip, mostly esprima pulled in by comment-json), so I looked at alternatives with my friend Opus 5.5.

candidate	gzip	notes
comment-json (#1381)	36-50 KB	reprints the whole file (expands inline arrays, drops trailing commas)
silver-fleece (main)	3 KB	drops comments
@croct/json5-parser	10-13 KB	ignores key reorder, minifies new files
jsonc-weaver	~150 KB	wasm (jsonc-morph), ignores key reorder
aywson	7-10 KB	breaks formatting
confbox	2 KB	parses comments, doesn't keep them
jsonc-parser + diff	6-9 KB	works, but broken ESM build / UMD main breaks Node + rolldown
own jsonc.ts (this PR)	2-3 KB	minimal text edits, keeps comments/commas/inline arrays, handles reorder

Net: sv-utils ends up ~15 KB gzip smaller than main, all tests pass (+ fuzzed 30k random JSONC edits).

So, do we want to own these ~330 lines of JSONC? That is the question!

[pkg-svelte-dev]

Install the latest version of sv from bb59023:

pnx https://pkg.svelte.dev/sv/c/bb5902362670b1f3dbf39456383b5e2086d05c78 create

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/cli/pr/1397

[changeset-bot]

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Latest commit: bb59023

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-cli-1397-svelte.vercel.app/

[sacrosanctic]

wow, can't believe we're going to publish our own jsonc parser. 😅

[manuel3108]

I'm not a huge fan of this to be honest. Give that we have seriously considered #80 over the last couple of months, and that would add svelte's 5MB as a dependency, I don't see a reason we should bother with 44KB.
Also if we would do this, we should publish this separately for the benefit of the ecosystem.

Or we could beg Rich to move golden-fleece into the org and work on that one (silver-fleece, which we were using before, is based on Rich's work)

[jycouet]

With #80 (that I'll want one day too), I'm not sure what will be the bundle size.

What's triggering me is the size + 2 other deps we add on our shoulders and ship.
It's not a must to split and publish it, as the goal is to serve our needs and not a global thing.
I was happy to see that it's not in 1000+ lines territory and that's why I suggest.

Maybe we can look into adding in golden/silver/steel stuff 😅