chore(dagu): adopt stamped omp-dagu 0.3.94 lifecycle renders #206

Problem

Backscroll currently adopts @a4s/omp-dagu 0.3.93. The retained-work replacement path failed for #201 because the retained delivery plus a real null-to-[] correction produced two commits before the one-candidate invariant. A4S PR pablontiv/a4s#453 merged source f34a300525812f2c87c351e832d9a24321ecadc1, version 0.3.94, including #375's original-base/initial-HEAD capture fix and #452's structured planning approvalIteration fix. Source publication, consumer adoption and runtime recovery are distinct outcomes.

Change

Prerequisite: coordinate delivery of the shared A4S primary at f34a300525812f2c87c351e832d9a24321ecadc1 (0.3.94), reload OMP and verify the actual loaded extension identity. Run bootstrap-backscroll-v0-3-94 from the clean canonical Backscroll primary using that delivered package. Preserve GATE=just check && just ci; REQUIRED_CHECK=candidate; TEST_PATHS=(^|/)tests/|_test.go$|^scripts/test-.*.sh$; empty REBASE_RESOLVER and VALIDATION; BASE_BRANCH=main. Enqueue this adoption lifecycle with the bootstrap-staged feature.yaml from the main Git directory, rather than the previously committed render. Version the four staged feature, poc, discovery and planning DAGs with the exact Dagu-Feature-Bundle, Dagu-Feature-Source and Dagu-Feature-Bootstrap trailers emitted by confirm. Update CONTRIBUTING.md, Dagu issue flow, to the actual adopted version, source and bootstrap identity while retaining the policy. Verify the installed reconciler, admission CLI and loaded coordinator extension match through the documented admission boundary. Existing issue owners, candidates and immutable snapshots retain their identities.

Acceptance

• Successful bootstrap records version 0.3.94, source pablontiv/a4s@f34a300, bootstrap-backscroll-v0-3-94, official Dagu 2.20.1 and the preserved policy.
• All four committed DAGs are byte-identical to their staged renders, verified with cmp using absolute staged paths printed by bootstrap. CONTRIBUTING.md states the same version/source/bootstrap as their headers.
• Targeted commands: dagu validate .workspace/dagu/dags/feature.yaml; dagu validate .workspace/dagu/dags/poc.yaml; dagu validate .workspace/dagu/dags/discovery.yaml; dagu validate .workspace/dagu/dags/planning.yaml. Full gate: just check && just ci. Record exact commands/results against the captured SHA.
• Fresh candidate-bound independent QA and review, required candidate CI, protected merge and reconciled cleanup pass. Record the adopted commit and bootstrap identity.

Scope

Lifecycle bundle adoption and existing adoption documentation only. #201 owns the first authorized replacement from the adopted producer and records retained delivery/correction, one-candidate/original-base bindings and fresh-gate evidence. #200 owns its separate stale-local-process runtime recovery verification. #159 owns OpenCode identity changes; #205 owns mixed-provider verification. The coordinator owns deployment and transitions. Retain the current CI contract and Definition of Done.

Breakdown source: refine