chore(main): release 3.1.0

[github-actions]

🤖 I have created a release beep boop

3.1.0 (2026-09-05)

Features

• prerequisite exposure telemetry and deferred tracking (4dac52f)

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This PR was generated with Release Please. See documentation.

[greptile-apps]

Confidence Score: 4/5

The release appears safe to merge, although its versioned changelog should be completed so users receive accurate release documentation.

The package and release versions are synchronized and no behavioral or security defect was found; the sole concern is incomplete documentation of functionality already included in 3.1.0.

Files Needing Attention: CHANGELOG.md

Prompt To Fix All With AI

### Issue 1
CHANGELOG.md:39
**Incomplete 3.1.0 release notes**

The 3.1.0 section only names prerequisite telemetry and deferred tracking, but this release also includes contextual-bandit support and several user-facing fixes that remain under Unreleased. Users relying on the versioned changelog therefore cannot see the full contents of 3.1.0. Move the applicable Unreleased entries into this section or summarize them here.

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For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "chore(main): release 3.1.0" | Re-trigger Greptile}

[github-actions]

🤖 Release is at https://github.com/growthbook/growthbook-python/releases/tag/v3.1.0 🌻