feat: emit qualified entity decision tasks v2

[abrichr]

Summary

• Add qualification-owned entity classes and qualify label set/remove/list.
• Publish one canonical reviewed class and fallback mapping for Flow, Desktop, and remote presentation.
• Emit signed HumanDecisionTaskV2 only after explicit remote peer schema negotiation.
• Preserve V1 with a neutral record or item fallback when any V2 gate fails.

Qualification and safety

V2 requires:

• A current passed qualification certification.
• Exact project revision and project, workflow, and policy contracts.
• The exact failed step and open pause capability.
• The exact current bundle version.
• A class and fallback pair from Flow's reviewed remote-safe vocabulary.

The emitter does not derive a class from screenshots, OCR, accessibility data, parameters, application names, or models. Legacy or unrecognized classes stay local and emit V1. Label changes revise the qualification contract and invalidate certification. The CLI gives the operator the exact recertification next step after a real mutation and keeps JSON output clean.

Validation

• 216 focused qualification, attended-action, and decision-delivery tests pass.
• Ruff and mypy pass.
• Wheel and sdist source-boundary validation passes.
• Independent contract and CLI reviews accept the current head.

Draft only. Merge and release with the coordinated Flow, Desktop, Cloud, Types, and documentation V2 train.