chore(main-qn): release 0.3.0+qn

[github-actions]

🤖 I have created a release beep boop

0.3.0+qn (2026-06-12)

Features

• measure first-seen vs duplicate-arrival lag per source pair (dup_lag) (eda6120)
• measure first-seen vs duplicate-arrival lag per source pair (dup_lag) (27ddabf)

Bug Fixes

• harden dup_lag rotation against idle gaps and concurrent first-seen (47a51b2)
• make dup_lag shard flip exclusive against observers (d9e75a6)
• rotate dup_lag shards on every arrival, not only sampled ones (e7f3945)

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This PR was generated with Release Please. See documentation.

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Note

Low Risk
Version and changelog-only changes with no runtime code in the diff; risk is limited to release tagging and dependency version alignment.

Overview
Release Please bumps the workspace from 0.2.14+qn to 0.3.0+qn in .release-please-manifest.json, Cargo.toml, Cargo.lock, and adds the 0.3.0+qn section to CHANGELOG.md. No application source files change in this diff.

The changelog for this tag records the shipped work since the last release: optional dup_lag metrics (first-seen vs duplicate-arrival lag per source pair, enabled via --measure-dup-lag) and follow-up fixes for shard rotation on every arrival, idle gaps, concurrent first-seen, and exclusive shard flips vs observers.

^{Reviewed by Cursor Bugbot for commit 134da65. Configure here.}

[github-actions]

🤖 Created releases:

• v0.3.0+qn

🌻