[BigBirdReturns]

Scope

This stacks on #23 and adds the first governed heterogeneous-runtime surface for Aperture:

• a six-stage runtime-adapter contract: probe, fit, prepare, launch, observe, stop;
• exact source pins and native adapters for SGLang MiniCPM5-2B + DSPARK and the MLX-LM HTTP server;
• CAIRN artifact intents, exact-revision materialization receipts, path redaction, and mandatory cleanup;
• deterministic placement across physical Seats while preserving distinct memory domains;
• occurrence/fence binding through the existing Estate authority plane rather than a second scheduler or lease system;
• a six-node synthetic dorm fixture and executable planner demonstration.

Source boundary

The SGLang adapter transcribes the official verified recipe at sgl-project/sglang@2bf04f3a67edf5f1c43b4f00761f19758346dcf7, docs/src/snippets/configs/openbmb/minicpm5-2b.jsx. It admits the upstream verified platform set or a separate exact local qualification receipt and preserves the recipe's remote-code requirement.

The MLX-LM adapter pins ml-explore/mlx-lm@7fb4be44d560e5b74595210f83cb6003a57e52a7, mlx_lm/server.py. It requires Apple silicon, Metal, the pinned server identity, an exact seat/model/source fit receipt, and current unified-memory headroom.

Verification

Local verification on the assembled tree:

node --check: PASS for every added .mjs file
node --test test/*.test.mjs: 19/19 PASS
node scripts/dorm-fabric-demo.mjs: READY_TO_PREPARE
synthetic demo output SHA-256: c38e4eb709cd09af14bd92d60a56992df132df5c5f63177408e349283d6e86c7

The synthetic planner assigns MiniCPM5-2B to the verified SGLang/RTX 5090 Seat, assigns a prequalified MLX artifact to the Apple-silicon Seat, leaves the optional ROCm job unplaced because no ROCm adapter exists, and emits three node-scoped CAIRN materialization intents across six distinct physical memory domains.

Claim boundary

This PR proves contracts, deterministic placement, refusal semantics, artifact-intent generation, authority binding, and receipt redaction against controlled fixtures. It does not claim a live dorm cluster, model download, runtime launch, throughput result, pooled VRAM, or additive memory capacity. Execution remains NOT_RUN until a fresh live census, exact runtime identities, fit receipts, CAIRN drivers, process drivers, and an Estate occurrence/lease/fence authorize the plan.

The authorized estate control path was disconnected during this work, so no remote host was modified and no live passage was attempted.