0.7: Refactor and land Inspect VM/workload support #310

Parent: #289. Inspect source: #291.

Work boundary 12/13 from the approved 0.7 → clients → Inspect sequence.

Dependencies: #300, #303, #309.

Carry #291 preserving Pierre’s authorship and features. Split modules/tests below source ceilings. Reuse SDK discovery, paths, errors and lifecycle ownership.

Acceptance criteria:

• Transfer byte limits and regular-file validation reject malformed/oversized/special-file inputs.
• Cleanup deletes only owned sessions.
• Host environment/path access requires evaluator-controlled grants.
• Inspect self-check and VM/workload acceptance run in the gate without optional live flags.
• Install and publish Inspect only after acceptance passes.

Planned PR boundaries: VM/workload core, SDK-backed security/lifecycle and gate acceptance before Compose.

Implementation progress and evidence: Sprinty in the isolated integration/0.7-clients-inspect worktree. Focused tests during development; fast checks/Citadel per PR; relevant black-box proof for runtime, credential or image boundaries. Respect the active release and machine locks.