fleet: require Daytona provider sandbox IDs for exact inspection and cleanup

[khaliqgant]

Problem

Relay 11.11.0 replaced Fleet snapshot-selector flags with caller-declared Cloud identities (--sandbox-id and --workspace-id). The resulting client contract requires the Cloud cleanup identity sandboxId, but providerSandboxId remains optional even when providerId is daytona.

Daytona CLI inspection and deletion operate on the provider UUID, not the Cloud sbx_... identity. If Cloud omits providerSandboxId, callers cannot bind Cloud to the exact Daytona sandbox, independently attest its snapshot, or perform ID-scoped cleanup after a cutoff. Falling back to name discovery weakens identity and cleanup guarantees.

This blocks the exhaustive clean-Daytona Fleet qualification in #1665 after #1705.

Expected contract

• Successful or timeout Daytona provisioning requires a valid providerSandboxId.
• Relay rejects a Daytona response that omits or malforms the provider ID.
• fleet spawn --sandbox --sandbox-provider daytona --sandbox-id ... --workspace-id ... exposes both the Cloud sandbox ID and Daytona provider UUID in its machine-readable result/evidence.
• Cleanup/recovery remains bounded and keyed to checkpointed identities.
• Other providers retain their explicitly supported identity semantics.

Acceptance

• Focused response-normalization, CLI, timeout, mismatch, and cleanup regressions.
• Exact-head CI and Veto diff review green.
• test(cleanroom): add exhaustive Relay and Fleet qualification #1665 harness uses the returned provider UUID for post-provision snapshot attestation and proves cleanup without ambient scanning.
• Full multi-node Daytona qualification passes before merge of the qualification flow.

[khaliqgant]

Fixed by PR #1733, merged as 6e44912. Exact head eed01ed passed hosted RelayFlow run 34479314451 attempt 2 (base bug/head fixed, 4/4 assertions), all hosted CI, focused tests/typechecks, resolved review threads, and Veto diff review PASS.