Drop the old runtime hub writer and mailbox/wake/projectImport path from mnemon-multica-runtime. Runtime issue handling now imports Multica surface input into mnemond without writing Multica metadata, comments, statuses, or managed wake side effects.

Validation: go test ./harness/cmd/mnemon-multica-runtime ./harness/internal/surface/multica

Remove MNEMON_HUB_BACKEND from Multica participant runtime env while still pruning stale values from existing agent env. Update Multica-hosted teamwork cues to keep canonical handoffs in Mnemon assignment events and treat Multica issues as OA and activation surfaces.

Validation: go test ./harness/cmd/mnemon-harness -run Multica; go test ./harness/internal/mnemond/presentation

Update coreguard to check the full mnemon-multica-runtime command now that the old hub writer is gone. The guard forbids managed wake and direct display writeback from the runtime input-import path, and pins mnemond/MnemonHub as Multica-surface agnostic.

Validation: go test ./harness/internal/coreguard ./harness/cmd/mnemon-multica-runtime

Keep the runtime final answer focused on Multica surface input import results. Remove the old projection, managed wake, and assignment mailbox summary helpers so the product output cannot imply R2 hub-backend behavior.

Validation: go test ./harness/internal/surface/multica ./harness/cmd/mnemon-multica-runtime

Replace managed-runtime participant env with MNEMON_MULTICA_PROVIDER_* settings so Multica provisioning describes the wrapped provider, not a Multica-owned wake scheduler. Keep stale MNEMON_MANAGED_* and MNEMON_HUB_BACKEND keys in the prune list for cleanup.

Validation: go test ./harness/cmd/mnemon-harness ./harness/internal/surface/multica ./harness/cmd/mnemon-acceptance

Delete the old Multica hub backend, assignment mailbox, and projection helpers. Replace driver exposure with R3 surface metadata aliases and update Multica acceptance to validate provider-wrapper surface flow instead of child mailbox fanout.

Validation: go test ./harness/internal/surface/multica ./harness/internal/driver ./harness/cmd/mnemon-acceptance ./harness/internal/mnemond/presentation ./harness/internal/drive ./harness/cmd/mnemon-harness

Run Multica turns through an optional provider command after surface ingest, preserving provider stdout as the final answer. Add explicit surface-report and activation-carrier commands for accepted-state display and execution routing, with surface_ref metadata and a surface write ledger replacing projection terminology.

Refresh Multica acceptance cases around Chinese R3 OA scenarios, provider wrapper readiness, display-only writeback, activation carriers, and child surface expectations. Validation: go test ./harness/cmd/mnemon-multica-runtime ./harness/cmd/mnemon-harness ./harness/cmd/mnemon-acceptance ./harness/internal/surface/multica ./harness/internal/driver ./harness/internal/coreguard ./harness/internal/mnemond/presentation ./harness/internal/drive; go build -o mnemon .

Replace projection_surfaces and projection worker terminology with display_surfaces, surface workers, and display-surface boundaries in product config and daemon status. This keeps Multica writeback as an explicit OA display surface instead of a separate projection layer.

Validation: go test ./harness/cmd/mnemon-multica-runtime ./harness/cmd/mnemon-harness ./harness/cmd/mnemon-acceptance ./harness/internal/surface/multica ./harness/internal/driver ./harness/internal/productconfig ./harness/internal/daemon ./harness/internal/coreguard ./harness/internal/mnemond/presentation ./harness/internal/drive; go build -o mnemon .

Keep the Multica runtime role guard terminology aligned with the R3 surface adapter boundary instead of projection writer language.

Validation: go test ./harness/internal/coreguard

Add live Multica R3 acceptance scripts and Chinese validation docs grounded in the native Multica runtime flow. Tighten acceptance so root and child surfaces must expose run messages, comments, metadata, and active agent evidence.

Update the Multica driver for current CLI/API shapes and pass imported issue context into provider commands without duplicate env keys.

Validation: go test ./harness/internal/driver; go test ./harness/cmd/mnemon-acceptance; go test ./harness/cmd/mnemon-multica-runtime; go test ./harness/internal/surface/multica; go test ./harness/cmd/mnemon-harness; bash -n scripts/multica_r3_live_*.sh; go build -o /tmp/mnemon-r3-build-check .; live cases r3-surface-readiness TEA-199, protocol-react-drill TEA-203, parallel-poc-overlap TEA-208 all status=ok.