Promote v0.2.0-dev.19 refactor queue

[Noah8218]

User-visible problem

The public repository is missing the verified Dev refactoring queue from v0.2.0-dev.8 through v0.2.0-dev.19. The final candidate also exposed a cancellation-observation race where a just-completed batch or commissioning validation could be reported as Idle during close.

Scope

• Port the twelve versioned public commits semantically onto public main without merging unrelated histories.
• Fix the shared AsyncOperationParticipant<TResult> boundary so cancellation remains observable until the next bounded observation, while preserving timeout mapping, caller exceptions, and one-shot cleanup.
• Keep private .proofline evidence, Dev-only governance, and the pre-existing sample sidecar out of the public allowlist.
• Candidate version: 0.2.0-dev.19.

Verification

• Exact local source tip: ae8c29c77628ef7e8ae894c10dd51df0a527b0e5.
• Release build: 0 warnings, 0 errors.
• Tests: Core 43/43, Infrastructure 46/46, Vision 31/31, Simulation 530/530, MachineStudio 439/439; total 1,089/1,089.
• Asset provenance: 6/6; vulnerable packages: 0; deprecated packages: 0.
• Self-contained win-x64 payload: 511 files; archive extraction differences: 0.
• Archive SHA-256: ED992E572A7407F178F3716603F2D0184654B7AA84706797A69F7F249D33DB87.
• Release manifest SHA-256: 4C93513F909EB90EC0D31D5245E7554018106D0F94A043EF9894E30C90BD3D15.
• Evidence: D:\OpenVisionLab-TestData\Machine\full-refactor-audit-20260909\promotion\final-release-candidate-v0.2.0-dev.19.

Review checklist

• Public metadata and README current version/history are aligned.
• Existing public names, schemas, and call paths are preserved by the semantic port.
• Required local release-candidate gate passes.
• No private evidence or untracked sample sidecar is included.
• Required Code Owner review.
• Required hosted release-candidate check.
• Required hosted fault-scenario-smoke check.

This PR is the protected-main path for the explicitly requested Original/Public integration. Tagging, release publication, and deployment remain separate actions.

[Noah8218]

Test