Feature: Multi-Tier Platform Enablement

[stijn-dejongh]

Feature: Multi-Tier Platform Enablement

Objective

Execute the Platform Next Steps assessment so router configs, orchestration
interfaces, local worker automation, diagrams, and CI guardrails exist for
the four-tier runtime outlined in ADR-020 and ADR-021.

Context

• Assessment: docs/architecture/assessments/platform_next_steps.md
• ADRs: 002 (portability), 009 (metrics), 020 (multi-tier runtime), 021 (model routing)
• Brainstorm inputs: work/notes/ideation/full_automatic_agents/brainstorm_part*.md

Current Signals

• No backlog items previously covered router config, local worker automation,
  or diagram/CI updates required by Alphonso’s plan.
• Distribution/Release work depends on these assets to be production-ready.

Execution Framework

• Use .github/agents/approaches/file_based_collaboration/ for every task,
  logging results per Directive 014.
• Bundle batches through .github/ISSUE_TEMPLATE/run-iteration.md when
  multiple artifacts (config + CI) are touched together.

Scope

• Create model router config + validator.
• Draft router-agnostic model_client interface.
• Extend task descriptors/directives with model selection hints.
• Operationalize Ollama worker config + runner.
• Produce diagrams for Layers 0-3.
• Integrate router and task-schema validators into CI.

Acceptance Criteria

• ✅ Router config validated and version-controlled with fallback rules.
• ✅ model_client interface documented and ready for integration.
• ✅ Template + directive updates merged; tasks start including model hints.
• ✅ Local worker script + config demoed in work log.
• ✅ Architecture diagrams rendered and referenced in docs/ADRs.
• ✅ CI fails fast when router config or task schema drifts.

Linked Tasks

• work/collaboration/inbox/2025-11-30T1201-build-automation-model-router-config.yaml
• work/collaboration/inbox/2025-11-30T1202-architect-model-client-interface.yaml
• work/collaboration/inbox/2025-11-30T1203-scribe-model-selection-template.yaml
• work/collaboration/inbox/2025-11-30T1204-build-automation-ollama-worker-pipeline.yaml
• work/collaboration/inbox/2025-11-30T1205-diagrammer-multi-tier-runtime-diagram.yaml
• work/collaboration/inbox/2025-11-30T1206-build-automation-ci-router-schema-validation.yaml