Prove workspace-bound continuation crash convergence

[zhiiw]

Summary

Adds the production-shaped crash proof for workspace-bound managed continuations and closes four durable seams exposed by that proof.

A real Runtime Host now starts a ContinuationClaimV2 against a real Gitoxide accepted head, is killed immediately after the durable continuation start, and is reopened against the same storage root and helper. Recovery closes the local Run as failed/app_restarted but keeps provider state parked as continuation_started_indeterminate; a new Turn retry does not invoke the provider.

Primary invariant

After a workspace-bound continuation start is durable, Host restart may only converge from the same v2 claim and exact accepted Gitoxide head. A local restart closure is not evidence that the provider never received the request. Recovery must not replay the provider and must not fall back to the v1 continuation authority.

• Owner: SQLite workspace-bound continuation authority
• Atomicity boundary: commitWorkspaceBoundContinuationStart() transaction
• Failure state: exact-head mismatch, missing v2 capability, or unverifiable helper fails closed; durable-start uncertainty parks
• Rollback: none for the immutable start fact; later policy must append a new explicit fact

Changes

• Exposes the v2 continuation authority through the restricted execution-store facade, using the existing SQLite writer.
• Adopts the durable storage-root binding when the packaged Gitoxide capability is admitted, before startup safety inspection.
• Strictly persists the workspace-bound root descriptor's independent replayManifestDigest while retaining the legacy descriptor shape.
• Validates continuation-start replay proof against the v2 descriptor rather than applying the v1 digest equality rule.
• Keeps runtime_admission + app_restarted provider state indeterminate; claim-repair and real terminal outcomes retain their existing classification.
• Adds a test-only continuation failpoint and a real Host/helper kill-and-reopen test with a durable provider-call oracle.
• Runs the proof on Linux, macOS, and Windows in the Gitoxide helper matrix.

Verification

• Core, Storage, Runtime, and Runtime Host builds pass.
• Legacy continuation process-crash harness passes all five committed prefixes.
• Workspace-bound AgentRun descriptor write/reopen regression passes.
• Gitoxide helper admission run 32682738656: Linux, macOS, and Windows all pass the real Runtime Host crash/restart proof.
• Provider invocation count remains zero before and after restart and after a new-Turn retry.

Stack

Depends on #28. This remains a stacked Draft and does not enable Desktop/CLI automatic continuation.

中文说明

摘要

本 PR 为 workspace-bound managed continuation 增加 production-shaped crash proof，并关闭该测试暴露出的四处 durable seam。

真实 Runtime Host 会针对真实 Gitoxide accepted head 提交 ContinuationClaimV2，在 durable continuation start 后立即被杀死，再使用同一个 storage root 和 helper 重启。Host 会把本地 Run 关闭为 failed/app_restarted，但这不能证明 provider 未收到请求，因此恢复仍停在 continuation_started_indeterminate；使用新的 Turn identity 重试也不会调用 provider。

主要不变量

workspace-bound continuation start 一旦持久化，Host 重启只能基于同一条 v2 claim 和同一个 accepted Gitoxide head 收敛；禁止重放 provider，也禁止回退 v1 continuation authority。

• **Owner：**SQLite workspace-bound continuation authority
• 原子性边界：commitWorkspaceBoundContinuationStart() transaction
• **失败状态：**head 不一致、v2 capability 缺失或 helper 无法验证时 fail closed；durable start 后的不确定状态 park
• **回滚：**不可变 start fact 不回滚；未来策略必须追加新的明确事实

三平台真实 crash gate 已通过：Linux、macOS、Windows 均验证 Host kill/reopen、exact Gitoxide head、app_restarted 本地关闭、continuation_started_indeterminate provider 状态以及零次 provider replay。

本 PR 仍是依赖 #28 的 stacked Draft，不会开启 Desktop/CLI 自动续跑。

[zhiiw]

Closed as an obsolete extraction/integration slice. The current delivery path is the merged Gitoxide foundation followed by #40 -> #41 -> #42. This PR remains available as design and implementation history.

中文说明

该 PR 属于旧 extraction/integration 栈，现已失去独立合并价值。当前交付路径是已合并的 Gitoxide 基础，然后依次审查 #40 → #41 → #42。这里继续保留设计、实现与审查历史。