Added 'Works by Decade Published' chart to reading log stats

[Saad259]

Closes #12805

Technical

Adds a "Works by Decade Published" chart to the reading log stats page. A new decade-chart type is introduced in readinglog_stats.js that preprocesses each work's first_publish_year into a decade string (e.g. 1987 → 1980s) before passing it to the existing createWorkChart function. Works with no first_publish_year are handled gracefully via the existing excluded works behaviour. A corresponding chart entry is added to the Work Stats section in readinglog_stats.html.

Testing

1. Ensure several books with varying publication years are added to 'Already Read'
2. Navigate to https://openlibrary.org/people/{username}/books/already-read/stats
3. Scroll to the Work Stats section
4. Verify that the "Works by Decade Published" chart appears as expected.

Screenshot

Stakeholders

@cdrini

[mekarpeles]

Thanks for the contribution!

🤖 Copilot has been assigned for an initial review.

@cdrini is assigned to this PR and currently has:

• 6 open PR(s) of equal or higher priority to review first

PR triage checklist (maintainers / Pam)

• PR description — not empty; explains what the change does and how to verify it
• References an issue — PR body contains a #NNN reference
  • Linked issue is triaged — has a Priority: * label (not just Needs: Triage)
  • Linked issue is assigned — has at least one assignee
• Commit history clean — no WIP/fixup/conflict noise; commit messages are meaningful
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• Test cases present — if the change touches substantive logic, test coverage exists or is explained
• Proof of testing — PR body includes a description of what was tested, a screenshot, or a video

Note

This comment was automatically generated by Pam, Open Library's Project AI Manager, on behalf of @mekarpeles. Pam is designed to provide status visibility, perform basic project management functions and relevant codebase research, and provide actionable feedback so contributors aren't left waiting.

[Copilot]

Pull request overview

Adds a new “Works by Decade Published” chart to reading log stats, using existing work publication-year data and the existing chart rendering flow.

Changes:

• Adds a decade-chart branch that derives decade labels from first_publish_year.
• Adds the new decade chart to the Work Stats section.
• Extends work typing metadata for publication year/decade data.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
openlibrary/plugins/openlibrary/js/readinglog_stats.js	Computes decade buckets and renders them through the existing work chart path.
openlibrary/templates/account/readinglog_stats.html	Adds the new chart configuration to the Work Stats charts list.

[cdrini]

Niiiice working swimmingly!

Hmmm could you add another graph for "Century published"? Books from the last 2 centuries will likely dominate this graph, but it would be interesting to also see data from the others!

[Saad259]

@cdrini Looking good?

[cdrini]

Wooohoooo looks great! I moved the first published graphs to the top, and tested on testing and works like a charm!