Switch from lodash to es-toolkit for esm support

[cuzzlor]

Problem: ESM output does not work, only CJS works

The prior PR adding dual ESM + CJS output does not actually work for ESM due to the continued use of CJS only lodash.
Lodash does not have a single dual output library, lodash-es is ESM only.

We cannot just replace lodash with a simple function because the omit-by-dot-notation keys functionality is important and is used for omit logging config.

Solution

Swap to es-toolkit which provides modern dual ESM + CJS output with 100% lodash compatibility.

Implementation notes

• Bumping to the next major version, since consumers will no longer get "full lodash" installed automatically via the peer dep.
• Keeping use of es-toolkit as a peer dep vs hard dep, since:
  • we don't want to force version numbers or constantly update this package past vulnerabilities
  • we expect ESM consumers may prefer opting in to control and use the version of es-toolkit at the consumer level (no loss)

[Copilot]

Pull request overview

This PR fixes broken ESM consumption by replacing lodash (CJS-only) imports with es-toolkit/compat (dual ESM+CJS), and bumps the package major version to reflect the peer dependency change.

Changes:

• Replace lodash imports with es-toolkit/compat in the omit-related winston formats.
• Swap the peer dependency from lodash to es-toolkit and remove @types/lodash.
• Update README to reference es-toolkit omit docs and bump package major version.

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/omit-nil-format.ts	Switch isNil/omitBy import to es-toolkit/compat for ESM compatibility.
src/omit-format.ts	Switch omit import to es-toolkit/compat for ESM compatibility.
package.json	Major version bump; peer dep swap from lodash to es-toolkit; remove @types/lodash.
package-lock.json	Reflect peer dep swap and lockfile package entries.
README.md	Update docs link/wording to reference es-toolkit compat omit.

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