fix(api): drop the duplicated container-repair helper

The restoration raced a sibling re-land of the same repair: the base
gained the helper between compose and push, so the merge introduced a
second definition of the same function and the build broke. The file
returns to the sibling's landing — one helper, wiring and suite intact,
cache-marker TTL fix untouched.

Author: jddunn

src/api/generateObject.ts

@@ -498,87 +498,6 @@ function summarizeZodErrors(error: ZodError): string {
   return lines.join('\n');
 }
 
-/**
- * Re-parses string-encoded containers where the schema expects an array or
- * object but the model produced a JSON STRING containing one.
- *
- * Models on the tool-use / structured-output path intermittently
- * double-encode a nested container — `{"verdicts": "[{...}]"}` instead of
- * `{"verdicts": [{...}]}` — most often on long, deeply nested payloads. The
- * raw text extracts as valid JSON, so only Zod sees the defect
- * (`invalid_type: expected array, received string`), and a retry re-rolls
- * the same dice with the same prompt.
- *
- * Driven strictly by the validation issues: for each `invalid_type` issue
- * expecting a container whose actual value is a string that syntactically
- * starts like that container, `JSON.parse` the string in place on a clone.
- * One pass, no recursion; anything that does not parse is left untouched so
- * the caller's normal retry/feedback path still applies.
- *
- * @param value - The extracted-but-invalid candidate value.
- * @param error - The Zod error from the failed validation.
- * @returns The (possibly repaired) value and whether any repair applied.
- * @internal
- */
-function repairStringEncodedContainers(
-  value: unknown,
-  error: ZodError,
-): { value: unknown; repaired: boolean } {
-  type ContainerIssue = { code?: string; expected?: string; path?: PropertyKey[] };
-  const targets = (error.issues as unknown as ContainerIssue[]).filter(
-    issue =>
-      issue.code === 'invalid_type' &&
-      (issue.expected === 'array' || issue.expected === 'object'),
-  );
-  if (targets.length === 0) return { value, repaired: false };
-
-  let root: unknown;
-  try {
-    root = structuredClone(value);
-  } catch {
-    // Non-cloneable input (should never happen for JSON-derived data) —
-    // repair is best-effort, never a new failure mode.
-    return { value, repaired: false };
-  }
-
-  let repaired = false;
-  for (const issue of targets) {
-    const path = issue.path ?? [];
-    // Resolve the offending node and its parent inside the clone.
-    let parent: Record<PropertyKey, unknown> | null = null;
-    let node: unknown = root;
-    for (const key of path) {
-      if (node === null || typeof node !== 'object') {
-        node = undefined;
-        break;
-      }
-      parent = node as Record<PropertyKey, unknown>;
-      node = parent[key];
-    }
-    if (typeof node !== 'string') continue;
-    const trimmed = node.trim();
-    const expectsArray = issue.expected === 'array';
-    if (expectsArray ? !trimmed.startsWith('[') : !trimmed.startsWith('{')) continue;
-    let inner: unknown;
-    try {
-      inner = JSON.parse(trimmed);
-    } catch {
-      continue;
-    }
-    if (path.length === 0) {
-      // The root itself was string-encoded.
-      root = inner;
-      repaired = true;
-      continue;
-    }
-    if (parent) {
-      parent[path[path.length - 1] as PropertyKey] = inner;
-      repaired = true;
-    }
-  }
-  return { value: root, repaired };
-}
-
 /**
  * Grows the output-token budget after a truncated attempt, capped at
  * {@link TRUNCATION_RETRY_MAX_TOKENS}. The provider layer clamps the result to