fix(plugin): normalize workspace package import paths in metadata generator

[maruthang]

PR Checklist

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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

PluginMetadataGenerator (via ModelClassVisitor and ControllerClassVisitor) computes relative paths from the source directory to the physical node_modules/ location of workspace packages. This produces import paths like ../node_modules/@amk/utils/src/dto/order.dto in the generated metadata, which causes TypeScript TS2742 errors at compile time.

Issue Number: #3453

What is the new behavior?

A normalizePackagePath helper is extracted in plugin-utils.ts. It detects when a resolved path passes through node_modules/ and strips everything up to that boundary, returning a bare package specifier (e.g., @amk/utils/src/dto/order.dto). Both ModelClassVisitor and ControllerClassVisitor now use this helper in their collectedMetadata() methods, so generated metadata always contains correct importable package paths.

Does this PR introduce a breaking change?

• Yes
• No

Other information

7 new unit tests added in test/plugin/normalize-package-path.spec.ts covering bare package paths, scoped packages, deep paths, and paths that should not be modified. All 152 tests pass.