feat(data): implement data tools

[chicogong]

Splits PR #152 for data tools. Implements the following tools:

• tools/data/bar-chart.html
• tools/data/chart-maker.html
• tools/data/correlation-analyzer.html
• tools/data/data-aggregator.html
• tools/data/data-cleaner.html
• tools/data/data-diff.html
• tools/data/data-exporter.html
• tools/data/data-filter.html
• tools/data/data-importer.html
• tools/data/data-merger.html
• tools/data/data-normalizer.html
• tools/data/data-sampler.html
• tools/data/data-sorter.html
• tools/data/data-transformer.html
• tools/data/data-validator.html
• tools/data/duplicate-remover.html
• tools/data/excel-to-json.html
• tools/data/heatmap-generator.html
• tools/data/histogram-generator.html
• tools/data/json-flattener.html
• tools/data/json-to-csv.html
• tools/data/json-unflatten.html
• tools/data/line-chart.html
• tools/data/outlier-detector.html
• tools/data/pie-chart.html
• tools/data/pivot-table.html
• tools/data/scatter-plot.html
• tools/data/sql-query-builder.html
• tools/data/statistics-calculator.html

🤖 Auto-split and verified by AI.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
html-tools	Error		Jun 30, 2026 7:43am

[netlify]

✅ Deploy Preview for localtools ready!

Name	Link
🔨 Latest commit	addb354
🔍 Latest deploy log	https://app.netlify.com/projects/localtools/deploys/6a4373b3ee81f0000828d6c5
😎 Deploy Preview	https://deploy-preview-172--localtools.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
🤖 Make changes	Run an agent on this branch

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[vercel]

Deployment failed with the following error:

The `vercel.json` schema validation failed with the following message: should NOT have additional property `public`

Learn More: https://vercel.com/docs/concepts/projects/project-configuration

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: addb354132

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Restore canonical metadata for data pages

For this page (and data-aggregator.html, data-diff.html, data-exporter.html, and data-importer.html) the commit removed the <link rel="canonical"> block entirely. The repository tests require every registered tool HTML to expose a canonical URL matching its tool path; running npm test -- --changed c5478eb5 now fails those checks, so these pages will block CI and lose their canonical URL metadata when published.

Useful? React with 👍 / 👎.