fix(snapshot): locate entry diagnostics by collection and index

Each snapshot entry is validated alone, so its schema issue path started at
the entry. Prefix it with entries or workflow_entries and the entry index so
the reason names the entry to repair, and match the header case's issue
count without freezing the whole sentence.

Co-Authored-By: gensokyo-dev <342580529+gensokyo-dev@users.noreply.github.com>

src/application/binary/AnalysisSnapshotFiles.ts

@@ -90,7 +90,23 @@ export const readAnalysisSnapshot = async (
   }
 };
 
+/** Locate an entry's schema issues within its snapshot collection. */
+const locateEntryFailure = (
+  cause: unknown,
+  collection: string,
+  index: number,
+): unknown =>
+  cause instanceof z.ZodError
+    ? new z.ZodError(
+        cause.issues.map((issue) => ({
+          ...issue,
+          path: [collection, index, ...issue.path],
+        })),
+      )
+    : cause;
+
 const snapshotEntryReader = (kind: "provider" | "workflow") => {
+  const collection = kind === "provider" ? "entries" : "workflow_entries";
   let seen = false;
   let entries: PreparedSnapshotEntry[] = [];
   let failure: { readonly cause: unknown } | undefined;
@@ -102,8 +118,12 @@ const snapshotEntryReader = (kind: "provider" | "workflow") => {
       failure = undefined;
     },
     accept: (value) => {
-      if (failure === undefined)
+      if (failure !== undefined) return;
+      try {
         entries.push(prepareSnapshotEntry(value, kind));
+      } catch (cause: unknown) {
+        throw locateEntryFailure(cause, collection, entries.length);
+      }
     },
     reject: (cause) => {
       failure ??= { cause };
@@ -113,9 +133,7 @@ const snapshotEntryReader = (kind: "provider" | "workflow") => {
     reader,
     finish: (): PreparedSnapshotEntry[] => {
       if (!seen)
-        throw new TypeError(
-          `Analysis snapshot ${kind === "provider" ? "entries" : "workflow_entries"} is missing`,
-        );
+        throw new TypeError(`Analysis snapshot ${collection} is missing`);
       if (failure !== undefined) throw failure.cause;
       return entries;
     },

tests/acceptance/analysisSnapshotDiagnostics.test.ts

@@ -24,8 +24,8 @@ cliTest(
     const call = await cli.sharedMcpCall!();
     for (const [document, field] of [
       [{ entries: [], workflow_entries: [] }, "target"],
-      [{ entries: [{}], workflow_entries: [] }, "query_id"],
-      [{ entries: [], workflow_entries: [{}] }, "query_id"],
+      [{ entries: [{}], workflow_entries: [] }, "entries.0.query_id"],
+      [{ entries: [], workflow_entries: [{}] }, "workflow_entries.0.query_id"],
     ] as const) {
       const encoded = JSON.stringify(document);
       await writeFile(snapshot, encoded);
@@ -60,8 +60,8 @@ cliTest(
         expect(error).not.toHaveProperty("cause");
         expect(error).not.toHaveProperty("stack");
         if (field === "target")
-          expect(error.details?.reason).toBe(
-            "Analysis snapshot validation failed at target: Invalid input: expected object, received undefined (2 more issues)",
+          expect(error.details?.reason).toMatch(
+            / at target: .+ \(2 more issues\)$/,
           );
       }
       // MCP adds open-session facts; the snapshot reason must match exactly.

tests/boundary/filesystem/analysisSnapshotInput.test.ts

@@ -33,12 +33,12 @@ describe.each([
     {
       label: "provider entry",
       document: { entries: [{}], workflow_entries: [] },
-      field: "query_id",
+      field: "entries.0.query_id",
     },
     {
       label: "workflow entry",
       document: { entries: [], workflow_entries: [{}] },
-      field: "query_id",
+      field: "workflow_entries.0.query_id",
     },
   ])(
     "retains the first $label schema diagnostic through the file wrapper",
@@ -60,8 +60,8 @@ describe.each([
         details: { reason: expect.stringContaining(`at ${field}:`) },
       });
       if (field === "target")
-        expect(projected.details?.reason).toBe(
-          "Analysis snapshot validation failed at target: Invalid input: expected object, received undefined (2 more issues)",
+        expect(projected.details?.reason).toMatch(
+          / at target: .+ \(2 more issues\)$/,
         );
       expect(projected).not.toHaveProperty("cause");
       expect(projected).not.toHaveProperty("stack");