chore(main): release 0.4.0

[github-actions]

🤖 I have created a release beep boop

0.4.0 (2026-05-15)

⚠ BREAKING CHANGES

• Replace tracker tuple from completion_config with AIConfig#create_tracker factory
• Track each AIConfigTracker metric at most once per tracker
• Add per-execution runId, at-most-once tracking, and cross-process tracker resumption

Features

• Add Client#create_tracker(token:, context:) to resume a tracker across processes (20f06f1)
• Add per-execution runId to correlate AIConfigTracker events (20f06f1)
• Add per-execution runId, at-most-once tracking, and cross-process tracker resumption (20f06f1)
• Replace tracker tuple from completion_config with AIConfig#create_tracker factory (20f06f1)
• Track each AIConfigTracker metric at most once per tracker (20f06f1)

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This PR was generated with Release Please. See documentation.

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Note

Low Risk
Release-only changes (version bumps and changelog/provenance updates) with no runtime code modifications, so functional risk is low.

Overview
Prepares the 0.4.0 release by bumping the gem version in lib/server/ai/version.rb and .release-please-manifest.json.

Updates CHANGELOG.md with the 0.4.0 release notes (including documented breaking changes/features) and refreshes PROVENANCE.md to reference the new version for attestation verification.

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[github-actions]

🤖 Created releases:

• 0.4.0

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