chore(release): prepare 0.3.4

[steipete]

Summary

• rewrite the 0.3.4 changelog from every commit since v0.3.3
• add highlights and grouped full entries while preserving the @stateanomaly thanks
• bump the CLI version to 0.3.4

This prepares the release only. It does not tag, publish, or create a GitHub release.

Proof

• go mod tidy -diff
• go run golang.org/x/vuln/cmd/govulncheck@latest ./...
• make ci
• make build
• native sonos --version, sonos --help, and discovery smoke test
• make build-darwin and universal binary inspection
• make docs-site
• actionlint
• pulled-base Docker build and CLI smoke test
• GoReleaser v2.17.0 config validation and snapshot build for all configured targets
• all seven snapshot archive checksums verified
• universal snapshot binary reports sonos 0.3.4
• AutoReview clean