[WIP] Why is the site artifact so big

[Copilot]

• Analyzed the repository structure and build process
• Built the current site and confirmed it's 1.3GB as reported
• Identified that _site/assets/images (1.3GB) is the primary culprit
• Found that fetch_image.js generates images at widths [null, 300, 720, 940, 1200]
• Discovered that 'null' preserves original size (generating 2048px+ images) and 1200px images are also very large
• Modified fetch_image.js to remove 'null' and 1200px widths, keeping only [300, 720, 940]
• Rebuilt the site and measured dramatic size reduction: 1.3GB → 371MB (71% reduction)
• Verified tarball size reduced to 329MB (was likely >1GB compressed before)
• Tested recent blog posts to ensure images still display properly
• Took screenshots showing images work correctly after optimization
• Updated .gitignore to prevent future build artifacts from being committed

Results Summary

Massive size reduction achieved:

• Uncompressed site: 1.3GB → 371MB (71% reduction)
• Compressed tarball: 329MB (estimated 70%+ reduction from original)
• Image files reduced: 1275 → 816 files

Solution:
Modified src/fetch_image.js to generate only necessary image sizes:

• Before: widths: [null, 300, 720, 940, 1200] (original + 1200px + others)
• After: widths: [300, 720, 940] (removed oversized variants)

The site max display width is 960px, so 1200px+ images were unnecessary and the 'null' (original size) was generating huge 2048px+ images.

Verification Screenshots

Homepage after optimization showing images load correctly:

Blog post with sensor data visualization displaying properly:

Fixes #285.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[dannystaple]

@copilot Can you try make your commits again, I've made the default .gitignore exclude tarballs and zips to prevent the error seen above.

[github-actions]

🦙 MegaLinter status: ❌ ERROR

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
❌ ACTION	actionlint	5		6	0	0.08s
✅ BASH	bash-exec	1		0	0	0.0s
✅ BASH	shellcheck	1		0	0	0.06s
⚠️ BASH	shfmt	1		1	0	0.0s
❌ C	cppcheck	8		8	0	0.3s
❌ CPP	cppcheck	8		8	0	0.33s
✅ JSON	npm-package-json-lint	yes		no	no	0.43s
✅ JSON	v8r	12		0	0	10.35s
❌ MARKDOWN	markdown-link-check	740		218	0	954.81s
✅ REPOSITORY	gitleaks	yes		no	no	13.02s
✅ REPOSITORY	git_diff	yes		no	no	0.38s
❌ REPOSITORY	grype	yes		2	no	35.21s
✅ REPOSITORY	secretlint	yes		no	no	41.87s
✅ REPOSITORY	syft	yes		no	no	1.65s
✅ REPOSITORY	trivy-sbom	yes		no	no	3.18s
✅ REPOSITORY	trufflehog	yes		no	no	4.87s
✅ XML	xmllint	1		0	0	188.45s
✅ YAML	v8r	13		0	0	6.82s

See detailed report in MegaLinter reports