feat: require exact Claude residency resume

[schickling-assistant]

Problem

Claude resume depends on both a native session ID and a transcript lineage. A stale hook or sibling transcript must not satisfy cold-start readiness.

Goal

Add exact Claude checkpoint, transcript validation, native resume, and readiness evidence.

Decisions

• Bind checkpoint identity to agent, runtime, generation, native session, workspace, transcript digest, and wrapper incarnation.
• Reject authored session selectors before provider spawn.
• Treat only the exact new session-start evidence as ready.
• Keep hook writes fenced so late events cannot overwrite another incarnation.

Verification

• cargo test --lib claude_session::tests -- --nocapture — 29 passed on the complete stack before the host-only cleanup; the exact readiness test passes after cleanup.
• cargo check --workspace passes on the complete stack.

Complexity

Claude has more evidence surfaces than Codex or OMP. The driver validates transcript lineage at the provider boundary instead of letting the host infer it.

Concerns

No fresh-session fallback exists. Invalid or ambiguous transcript evidence refuses resume.

Friction & bottlenecks

None specific to this layer.

Follow-ups

PR #494 composes all three provider capabilities under host policy.

References

Depends on PR #492. Part of stack #495.

Posted on behalf of @schickling

field	value
agent_identity	mbp2025.direct.omp.bn5hrz39
session	mbp2025.bn5hrz39
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.1.7
agent_runtime	OMP 18.1.7
tooling_profile	dotfiles@4816a7a