ci: enforce a 250 KB gzip JS budget per page

[aynazar-sylyyew-dev]

Closes #6 (hard CI budget for JS shipped per page).

What changed

• scripts/check-size.mjs — new CI script, Node built-ins only (node:fs, node:zlib, node:path), zero new dependencies.
  • Recursively finds every index.html in out/.
  • Extracts every <script src="/_next/…"> the page loads (deduped).
  • Sums zlib.gzipSync sizes of those files and prints a per-page table (page, KB gzip).
  • Exits with code 1 if any page exceeds the budget. The budget is a single constant LIMIT_KB at the top of the file.
• package.json — adds "check:size": "node scripts/check-size.mjs".
• .github/workflows/deploy.yml — runs npm run check:size after npm run build and the store-pages check, before upload-pages-artifact. An over-budget build fails the build job and never reaches deployment; every PR to main gets the check.

Current numbers (static export, Next.js 16.3.6)

Page	KB gzip
/	173.21
/ru/	173.21
/en/	173.21
/projects/	173.54
/ru/projects/	173.54
/en/projects/	173.54
/404/, /_not-found/	169.39

All pages are ~174 KB today, so the 250 KB budget passes with ~76 KB of headroom for the upcoming animations work.

Proof the check actually fails

• Commit 95e3d8d sets LIMIT_KB = 100 → its CI run is red: all 8 pages (~173 KB) exceed the budget and the build job fails at the "Check bundle size limit" step.
• Commit 87644e8 restores LIMIT_KB = 250 → CI is green again.
  Both runs are visible in the Checks timeline and in the Actions tab.

Why

Internet in Turkmenistan is slow and expensive. The old site shipped ~3 KB of JS; the Next.js migration took that to ~174 KB per page. A hard, CI-enforced budget prevents further silent growth (animations are next).

[TheSeydiCharyyev]

Checked 87644c8 locally and in CI. The table matches my build (173.21 / 173.54 KB), the 100 KB commit is red, the 250 KB head is green, and the step runs before the upload. Good.

Two things before merge:

1. A missing script is counted as 0 KB (getGzipSize catches the error and returns 0). I deleted one 28.9 KB chunk that / loads and ran the script: it printed 165.78 KB for / and exited with code 0. A budget check must not pass with a lower number when a file is missing. Please remove the try/catch there, and if a /_next/ file that a page references does not exist, print the page and the file and exit with code 1. Also match src.startsWith('/_next/') instead of src.includes('/_next/'), so a full URL is never mapped to a local path.

2. Please remove "start": "next start" from package.json. It is not part of #6, and it does not work with our static export: npm start fails with "next start" does not work with "output: export" configuration.

Small thing: deploy.yml now ends with a line of spaces and no newline. Please remove that line.

[aynazar-sylyyew-dev]

All three points addressed in the new commit:

• getGzipSize no longer swallows errors. A referenced /_next/ file that does not exist is printed as page <route> -> <path> and the check exits 1 (verified locally by renaming a chunk: the page is flagged in the table and the run fails).
• Src matching is now src.startsWith('/_next/'), so absolute URLs are never mapped into out/.
• "start": "next start" removed from package.json.
• deploy.yml no longer ends with a spaces-only line; the file now ends with a single newline.

[TheSeydiCharyyev]

Checked 7703086. I deleted the same 28.9 KB chunk again: the script now marks every page with "1 missing", lists page -> file, and exits with code 1. On a normal build it passes with 173.21 / 173.54 KB. next start is gone and deploy.yml ends with one newline. CI is green.

Tiny and optional: "scripts": { in package.json is indented with 4 spaces, the rest of the file uses 2.