Dependency maintenance: consume ESPressio Units 0.2.2

[LK-Simon]

Summary

Refresh Timing's required Units baseline after the Serializable 0.10.1 -> Units 0.2.2 cascade.

Scope

• Prepare ESPressio Timing 2.2.3.
• Update required Units references from 0.2.1 to 0.2.2 in current documentation, dependency charts, tests/workflows, examples, and metadata where applicable.
• Keep Timing independent of ESPressio Serializable; Serializable remains reachable only through opt-in Serializable Unit representations.
• Update CHANGELOG and self-version documentation.
• Validate against Units 0.2.2 and Observable 3.0.1.

Dependency direction

Timing -> Units -> optional Serializable. Timing must not acquire a direct Serializable dependency.

Release order

Serializable 0.10.1 -> Units 0.2.2 -> Timing 2.2.3.