Make sticky_contents default to True

[mmcky]

Summary

Makes sticky_contents default to True so the sticky right-hand table of contents with scroll spy is enabled out of the box.

The sticky TOC was introduced in v0.17.0 (#350) and has proven to be the preferred experience. This change makes it the default for all projects using the theme — no configuration needed.

Changes

• theme.conf — changed sticky_contents = False → sticky_contents = True
• configuration.md — updated docs to describe sticky TOC as the default, with instructions on how to disable it
• test_build.py — updated tests to expect sticky TOC enabled by default and added a test for explicitly disabling it
• CHANGELOG.md — added unreleased entry

Opting out

Projects that prefer the classic TOC can set:

html_theme_options = {
    "sticky_contents": False,
}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

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[Copilot]

Pull request overview

This PR changes the QuantEcon Book Theme’s default behavior to enable the sticky right-hand table of contents (“scroll spy” TOC) out of the box, aligning the default theme experience with the feature introduced in v0.17.0.

Changes:

• Switch sticky_contents default from False to True in the theme’s default configuration.
• Update user documentation to describe sticky TOC as the default and document how to opt out.
• Update build tests and changelog to reflect the new default behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/test_build.py	Updates expectations so sticky TOC is enabled by default and adds coverage for explicitly disabling it.
src/quantecon_book_theme/theme/quantecon_book_theme/theme.conf	Sets sticky_contents = True as the theme default option.
docs/user/configuration.md	Reframes sticky TOC docs as default-enabled and provides opt-out instructions.
CHANGELOG.md	Adds an Unreleased entry noting the default change and how to revert.

Comments suppressed due to low confidence (1)

docs/user/configuration.md:195

• The “Disable auto-expansion” section now shows only "contents_autoexpand": False. Since contents_autoexpand only affects the sticky TOC, it would be clearer to explicitly state that this option has an effect only when sticky_contents is enabled (now the default), so readers don’t expect it to change the classic/non-sticky TOC.

### Disable auto-expansion

```python
html_theme_options = {
    ...
    "contents_autoexpand": False,
    ...
}

When contents_autoexpand is False, only top-level section names are displayed.

</details>



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[github-actions]

🎭 Visual Regression Test Results

 45 passed
 1 skipped

Details

 46 tests across 1 suite
 1 minute, 3 seconds
 51942cc

Skipped tests

mobile-chrome › theme.spec.ts › Theme Features › f-string interpolation styling

[github-actions]

🚀 Deployed on https://69a7c7c848daffb220fff3cb--hungry-lovelace-7d0512.netlify.app

[mmcky]

Also addressed in 51942cc (suppressed suggestion on docs/user/configuration.md). Added a note to the "Disable auto-expansion" section making clear that contents_autoexpand only has an effect when the sticky TOC is enabled — it has no impact when sticky_contents is set to False.

Also confirming: contents_autoexpand is True by default (set in theme.conf), so auto-expansion is on out of the box alongside the now-default sticky TOC.

[mmcky]

• review Code block background renders dark in light mode (cell_input) #372 before merge and release