Description

Currently we check for a module existence via url in ensureEntryForUrl, but a url could map to the same resolved id that already exists in idToModulesMap (e.g. via a different url that also resolves to the same id).

This can currently happen for two URLs like:

• /Users/foo/bar/project/src/index.js
• /src/index.js

This PR changes to check the resolved id instead, and update the url to use the existing id & module if possible.

Additional context

Ref withastro/astro#4378
Feels related to #9730 and #7845
Something similar has been happening in SvelteKit too

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.