Track Echo scheduler-runtime dependency #4

Dependency

Source endpoints:

• Run compiler-produced Hello Echo through scheduler-owned Ticks echo#690 — closed; generic compiler-produced runtime witness exists.
• Preserve typed obstruction identity in executable operation packages echo#696 — closed; typed application obstruction identity is retained in the executable package and generic runner report.
• Expose duplicate no-mutation evidence from the generic runner echo#699 — closed through Expose duplicate state evidence from the generic runner echo#700 at 63482dc4dd219d51769b79b80173610ca180f7d2; generic before/after application-state roots and target-value digests are exposed with fail-closed mutation rejection.

Blocked target:

• Prove durable scheduler-owned Hello Echo execution #3 — closed through Prove durable Hello Echo execution #17 at 5eb43a0.

Current status: Echo owns package admission, WAL-backed Action submission, scheduler evaluation, outcomes, Receipts, recovery, and independently comparable duplicate no-mutation evidence. Hello Echo consumes the generic evidence across its complete runtime witness matrix.

Completion rule

Satisfied on 2026-07-28: flyingrobots/echo#699 is merged and the standalone Hello Echo witness consumes the published generic runner evidence.