refactor(model): let format parsers own tensor range validation

src/model/GgufHeader.ts

@@ -429,6 +429,15 @@ export class GgufHeader {
       storage_validation:
         tensor.byte_length === null ? "unknown" : "consistent",
     }));
+    const intervals = completeTensors
+      .filter((row) => row.byte_length !== null)
+      .sort((a, b) => a.file_offset - b.file_offset);
+    let end = tensor_data_offset;
+    for (const row of intervals) {
+      if (row.file_offset < end && row.byte_length !== 0)
+        rejectModel(`Overlapping tensor byte ranges at ${row.name}`);
+      end = Math.max(end, row.file_offset + (row.byte_length ?? 0));
+    }
     return {
       version,
       byte_order: this.#little ? "little" : "big",

src/model/ModelArtifactProvider.ts

@@ -40,7 +40,6 @@ import { GgufHeader } from "./GgufHeader.js";
 import { readSafetensorsHeader } from "./SafetensorsHeader.js";
 import {
   ModelFormatFailure,
-  rejectModel,
   rejectPickle,
   MODEL_REPORT_BYTES,
   modelCapacityRemediation,
@@ -311,15 +310,6 @@ export class ModelArtifactProvider implements ModelArtifactPort {
             onLimitation: (message) => partial.limitations.push(message),
           })
         : await readSafetensorsHeader(reader, first);
-    const intervals = parsed.tensors
-      .filter((row) => row.byte_length !== null)
-      .sort((a, b) => a.file_offset - b.file_offset);
-    let end = parsed.tensor_data_offset;
-    for (const row of intervals) {
-      if (row.file_offset < end && row.byte_length !== 0)
-        rejectModel(`Overlapping tensor byte ranges at ${row.name}`);
-      end = Math.max(end, row.file_offset + (row.byte_length ?? 0));
-    }
     partial.version = parsed.version;
     partial.byte_order = parsed.byte_order;
     partial.alignment = parsed.alignment;

tests/boundary/model/modelArtifact.test.ts

@@ -15,6 +15,7 @@ import {
 import { readSafetensorsHeader } from "../../../src/model/SafetensorsHeader.js";
 import { GgufHeader } from "../../../src/model/GgufHeader.js";
 import { createModelArtifactService } from "../../../src/composition/model.js";
+import { parseEvidence } from "../../../src/domain/evidence.js";
 import { modelArtifactSchema } from "../../../src/domain/model/modelArtifact.js";
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 import {
@@ -1063,6 +1064,48 @@ it.each(malformed)(
   },
 );
 
+it("retains GGUF declarations and metadata when storage overlap is refused", async () => {
+  const seed = ggufFixture();
+  const fixture = ggufFixture({
+    metadata: [{ key: "general.name", type: 8, value: seed.text("Overlap") }],
+    tensors: [
+      { name: "a", type: 0, shape: [1n], offset: 0n, bytes: 4 },
+      { name: "b", type: 0, shape: [1n], offset: 0n, bytes: 4 },
+    ],
+  });
+  const { provider, path } = await providerAt(fixture.bytes);
+  const result = await provider.inspect({ path, hash: "header" });
+  if (result.ok) throw new Error("Overlapping tensors admitted");
+  expect(result.error).toMatchObject({
+    _tag: "BinaryTargetError",
+    constraint: "file_format_rejected",
+  });
+  const evidence = parseEvidence(result.error.partialObservation);
+  expect(evidence.subject).toBeNull();
+  expect(evidence.normalized_result).toMatchObject({
+    artifact: {
+      header_sha256: null,
+      sha256: null,
+      file_identity: "unverified",
+    },
+    coverage: { header: "partial", metadata: "complete", tensors: "partial" },
+    metadata: [{ key: "general.name", value: "Overlap" }],
+    tensors: [],
+    tensor_declarations: [
+      {
+        name: "a",
+        file_offset: fixture.dataOffset,
+        storage_validation: "not-established",
+      },
+      {
+        name: "b",
+        file_offset: fixture.dataOffset,
+        storage_validation: "not-established",
+      },
+    ],
+  });
+});
+
 it("accepts null safetensors metadata and ignores tensor extension fields", async () => {
   const fixture = safetensorsFixture(
     '{"__metadata__":null,"weight":{"dtype":"F32","shape":[1],"data_offsets":[0,4],"note":{"source":"local","flags":[null,false,-1,1.25]}}}',