v0.18.6

Spawn v0.18.6 introduces the proof-enabled execution stack.

Highlights

• Witnessed execution records by default for each run
• Explicit capture and completeness semantics in verification
• Deterministic portable proof bundles with off-host verification parity
• Detached attestation over the canonical record digest
• Local trust-store and trust-aware verification policy
• Mobile demo UI for runbook and command selection

This release moves Spawn from a launcher toward a witnessed, portable, and attestable execution layer.