The `findByPath()` method was failing to return results when using nested
dot-notation paths such as `user.email` or `items.1`. However, it’s returning
`null` instead of the expected result in some cases.
The root cause was a mismatch between how paths are stored vs searched:
- Storage: Validators like Key and Each create results where the path is stored
as a linked list. For `user.email`, the "email" result has `path="email"` with
`parent="user"`.
- Search (old): The method expected a tree structure where it would find a child
with `path="user"`, then search that child for `path="email"`. But no child
had `path="user"` - only "email" (with "user" as its parent).
The fix computes each result's full path by walking up the parent chain and
compares it against the search path. Also converts numeric strings to integers
when parsing paths (e.g., `items.1` → `['items', 1]`) since array indices are
stored as integers.
While working on this fix, I also realised that to expose the result's status,
it’s best to use `hasFailed()` instead of `isValid()` in `ResultQuery`, since
users will mostly use results when validation failed, not when it passed.
Assisted-by: Claude Code (Opus 4.5)
