feat(data): add read-only artifact health monitor

tests/test_artifact_health_api.py

@@ -0,0 +1,83 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+from k1link.compute.e44_data_amplification_audit import (
+    build_e44_data_amplification_audit,
+)
+from k1link.web.artifact_health_api import ArtifactHealthService
+
+
+def _write(path: Path, payload: bytes) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_bytes(payload)
+
+
+def test_artifact_health_reports_live_inventory_and_exact_audit(tmp_path: Path) -> None:
+    runtime = tmp_path / ".runtime"
+    first = runtime / "compute-experiments" / "e30" / "result-a"
+    second = runtime / "compute-experiments" / "e40" / "result-b"
+    _write(first / "shared.bin", b"shared")
+    _write(first / "only-a.bin", b"a")
+    _write(second / "shared.bin", b"shared")
+    _write(second / "only-b.bin", b"bb")
+    e44_results = runtime / "compute-experiments" / "e44" / "results"
+    build_e44_data_amplification_audit(
+        artifact_roots={"e30": first, "e40": second},
+        output_root=e44_results,
+    )
+
+    service = ArtifactHealthService(
+        lambda: runtime,
+        lambda: e44_results,
+        cache_seconds=0,
+    )
+    document = service.snapshot()
+
+    assert document.inventory.state == "live"
+    assert document.inventory.file_count >= 6
+    assert document.inventory.logical_bytes > 0
+    assert document.exact_audit.state == "exact-current"
+    assert document.exact_audit.duplicate_bytes == len(b"shared")
+    assert document.content_references.state == "not-indexed"
+    assert document.content_references.storage_migration_authorized is False
+
+
+def test_artifact_health_marks_exact_audit_stale_after_source_change(
+    tmp_path: Path,
+) -> None:
+    runtime = tmp_path / ".runtime"
+    first = runtime / "e30" / "result-a"
+    second = runtime / "e40" / "result-b"
+    _write(first / "a.bin", b"a")
+    _write(second / "b.bin", b"b")
+    e44_results = runtime / "e44" / "results"
+    audit = build_e44_data_amplification_audit(
+        artifact_roots={"e30": first, "e40": second},
+        output_root=e44_results,
+    )
+    manifest = json.loads((audit.result_root / "manifest.json").read_text())
+    first_name = manifest["identity"]["artifact_roots"][0]["root_name"]
+    _write(first / "new.bin", b"new")
+
+    document = ArtifactHealthService(
+        lambda: runtime,
+        lambda: e44_results,
+        cache_seconds=0,
+    ).snapshot()
+
+    assert document.exact_audit.state == "exact-stale"
+    assert first_name in document.exact_audit.changed_roots
+
+
+def test_artifact_health_reports_unavailable_runtime(tmp_path: Path) -> None:
+    document = ArtifactHealthService(
+        lambda: tmp_path / "missing",
+        lambda: tmp_path / "missing-e44",
+        cache_seconds=0,
+    ).snapshot()
+
+    assert document.overall_state == "unavailable"
+    assert document.inventory.state == "unavailable"
+    assert document.exact_audit.state == "unavailable"