feat(sync): add edge artifact authority model

core/sync/artifacts.py

@@ -0,0 +1,144 @@
+"""Artifact authority model for edge/cloud synchronization.
+
+The model is pure and has no object-store dependency.  It encodes the
+contract from docs/architecture/edge-sync-artifact-contract.md so tests
+can prove that storage, signature, activation, and evidence authority
+remain separate.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import Enum
+
+
+class ArtifactType(str, Enum):
+    """Closed artifact classes allowed at the edge/cloud boundary."""
+
+    TRACE = "trace"
+    REPLAY_BUNDLE = "replay_bundle"
+    SEALED_EVAL_RESULT = "sealed_eval_result"
+    FLEET_OBSERVATION_BATCH = "fleet_observation_batch"
+    CURRICULUM_BUNDLE = "curriculum_bundle"
+    PACK_RELEASE = "pack_release"
+    POLICY_RELEASE = "policy_release"
+    MODALITY_COMPILER_RELEASE = "modality_compiler_release"
+    COLD_VAULT_SNAPSHOT = "cold_vault_snapshot"
+
+
+@dataclass(frozen=True, slots=True)
+class ArtifactAuthority:
+    """Authority profile for one artifact class.
+
+    These fields are intentionally independent.  A signed artifact may
+    prove integrity without becoming evidence; an activated artifact may
+    participate in runtime behavior without making every contained claim
+    coherent.
+    """
+
+    runtime_affecting: bool
+    hot_path_allowed: bool
+    requires_signature: bool
+    requires_activation: bool
+    requires_review_or_proof: bool
+    default_epistemic_status: str
+    admissible_as_evidence: bool
+
+
+ARTIFACT_AUTHORITY: dict[ArtifactType, ArtifactAuthority] = {
+    ArtifactType.TRACE: ArtifactAuthority(
+        runtime_affecting=False,
+        hot_path_allowed=False,
+        requires_signature=False,
+        requires_activation=False,
+        requires_review_or_proof=False,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.REPLAY_BUNDLE: ArtifactAuthority(
+        runtime_affecting=False,
+        hot_path_allowed=False,
+        requires_signature=False,
+        requires_activation=False,
+        requires_review_or_proof=False,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.SEALED_EVAL_RESULT: ArtifactAuthority(
+        runtime_affecting=False,
+        hot_path_allowed=False,
+        requires_signature=False,
+        requires_activation=False,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.FLEET_OBSERVATION_BATCH: ArtifactAuthority(
+        runtime_affecting=False,
+        hot_path_allowed=False,
+        requires_signature=False,
+        requires_activation=False,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.CURRICULUM_BUNDLE: ArtifactAuthority(
+        runtime_affecting=False,
+        hot_path_allowed=False,
+        requires_signature=True,
+        requires_activation=False,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.PACK_RELEASE: ArtifactAuthority(
+        runtime_affecting=True,
+        hot_path_allowed=False,
+        requires_signature=True,
+        requires_activation=True,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.POLICY_RELEASE: ArtifactAuthority(
+        runtime_affecting=True,
+        hot_path_allowed=False,
+        requires_signature=True,
+        requires_activation=True,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.MODALITY_COMPILER_RELEASE: ArtifactAuthority(
+        runtime_affecting=True,
+        hot_path_allowed=False,
+        requires_signature=True,
+        requires_activation=True,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+    ArtifactType.COLD_VAULT_SNAPSHOT: ArtifactAuthority(
+        runtime_affecting=True,
+        hot_path_allowed=False,
+        requires_signature=True,
+        requires_activation=True,
+        requires_review_or_proof=True,
+        default_epistemic_status="speculative",
+        admissible_as_evidence=False,
+    ),
+}
+
+
+def authority_for(artifact_type: ArtifactType | str) -> ArtifactAuthority:
+    """Return the authority profile for an artifact type.
+
+    Raises:
+        ValueError: if the artifact type is unknown.
+    """
+
+    try:
+        normalized = artifact_type if isinstance(artifact_type, ArtifactType) else ArtifactType(artifact_type)
+    except ValueError as exc:
+        raise ValueError(f"unknown artifact type: {artifact_type!r}") from exc
+    return ARTIFACT_AUTHORITY[normalized]