tasks/format-code-task-000028/instruction.md

Fix the following issue:

Add a validateAllPaths validation option for documents

Mongoose documents already let you narrow down what gets validated. For example, a schema configured with validateModifiedOnly: true only runs validators on paths that were actually modified, and callers can pass pathsToValidate / pathsToSkip to further restrict the work.

We need the opposite escape hatch: a way to force validation of every path defined on the schema, regardless of what has (or hasn't) been modified.

Add a validateAllPaths boolean option that is accepted by both the asynchronous validate() method and the synchronous validateSync() method (via their options object). When validateAllPaths is true:

• Validation runs against every path declared in the schema, including paths whose values were never modified. This takes precedence over a schema-level validateModifiedOnly setting, so an unmodified-but-invalid path is reported as an error even when the schema would normally skip it.
• Each element of an array path is validated too, so element-level validators (e.g. enum on the items of a string array) run against every element. A failing element is reported under its indexed path (for example tags.0).
• A document whose paths are all valid still passes: validateSync() returns undefined and validate() resolves.

The option is mutually exclusive with the existing path-narrowing options. Combining validateAllPaths with any of the following must raise a TypeError (and validate() must reject with it) before any validation runs, using these exact messages:

• with pathsToSkip → Cannot set both \validateAllPaths` and `pathsToSkip``
• with pathsToValidate → Cannot set both \validateAllPaths` and `pathsToValidate``
• with a validateModifiedOnly option → Cannot set both \validateAllPaths` and `validateModifiedOnly``

These rules apply identically to validate() and validateSync().