feat(workflow): §4a thin runtime_run loop — RunnableFrontier → eval_with_context → receipt append (wave-1 sequential, bounded)

[briansrls]

Summary

• Adds src/v4/workflow/runtime_run.dag: thin sequential run loop over RunnableFrontier
  • runtime_run(nodes, dependencies, tree, context) -> RuntimeRunResult — bounded fold (mirrors scheduler_run_to_fixed_point); each step calls eval_with_context per ready node and appends a RuntimeRunReceipt
  • runtime_run_step_from_frontier(frontier, state, tree, context) -> RuntimeRunState — callable entry for §4b (program.dag) to target
  • RuntimeRunComplete | RuntimeRunBlocked result with 🟡 dissolution mark for host-transport verdict return
• Adds src/v4/test/claim/manual/runtime_run.dag: BoolWitnessClaim gate witness
  • Per-node InferredFacts lookup (not constant map — avoids grounding-node mismatch)
  • Three claims: single-step receipt append, full two-node sequential run reaches RuntimeRunComplete, step is bounded to its frontier
  • unified_claim_runtime_run: UnifiedTestClaim

Why

Wave-1 §4a substrate: exposes the callable entry runtime_run_step_from_frontier that §4b (program.dag run) targets. Bounded by fold(nodes, ...) so termination proof mirrors scheduler_run_to_fixed_point. Fail-closed per node: RuntimeRunReceipt captures both Accepted and Rejected so no eval outcome is silently dropped (P3).

Tests

cargo test --workspace — 18/19 pass; the 1 failure (workflow_no_path_regex_policy_ci_yml) is a pre-existing worktree-environment issue with git ls-files from the .worktrees/ parent directory, not present in CI.

cargo clippy --all-targets -- -D warnings — 3 pre-existing errors in src/v3/compiler/src/emit_host_eval.rs (not touched by this PR).

[briansrls]

Superseded by #4743, which includes the same §4a runtime_run substrate (workflow/runtime_run.dag + manual/runtime_run.dag gate witness) plus §4c program.dag integration. Avoids duplicate merge of runtime_run.

[briansrls]

Dashboard feedback triage (royal-ferret-510) — no action on this PR.

#4745 is CLOSED (superseded by #4743, 2026-06-12). §4a scope (workflow/runtime_run.dag + manual/runtime_run.dag) is included in #4743 plus §4c program.dag integration and the witness fixture fix (distinct TypeNode atom symbols for scheduler dedup).

Dashboard api-review APPROVE artifacts (#28672 claude, #28674 cursor) on this closed PR are historical — active lane is #4743 (68c5c48bc4). No reopen, no duplicate merge.

— sent from royal-ferret-510