feat: add attended reconciliation contract

[abrichr]

What changed

• Adds a portable reconcile attended action for uncertain deliveries and effect checks.
• Keeps reconciliation distinct from continue: it asks the runner to prove the prior business effect and never authorizes re-dispatch.
• Adds a closed reconciled_and_resumed terminal reason.
• Binds completed reasons to the exact action that produced them.
• Requires completed receipts to carry report_success=true and a transition receipt.
• Refuses to advertise reconciliation before an action was delivered or delivery became uncertain.
• Regenerates the packaged language-agnostic task and receipt schemas.

Why

The operator loop needs a truthful way to reconcile a possibly completed write without pretending it is an ordinary continuation or authorizing a duplicate retry.

Validation

• 236 tests passed.
• Wheel and sdist built and inspected.
• Packaged schemas exactly match the Python contract.
• Source tree and built archives passed the source-policy boundary.
• Independent exact review rejected the first draft, reproduced its false-success cases, and accepted corrected head dd8be1e971c3538b4d2fd78dab335dd018a7e7d0.

This PR intentionally remains draft until Flow, Cloud, and Desktop consume the closed action and the coordinated Types 0.7 / Flow 1.26 release is authorized.

[abrichr]

Superseded by #21, which combined this reconciliation contract with the Execute v1 contract and regenerated the shared schema. The coordinated result is now published as openadapt-types 0.7.0.