[App Router] Configurable redirects locale prefix behavior

[art-alexeyenko]

Description / Motivation

• Reverts the changes around isLanguagePreserved from [nextjs] Fix pending redirects issues #568
• Expands on the configuration from [nextjs][create-content-sdk-app] RedirectsProxy doesn't work if LocaleProxy is removed #563 to provide a choice on behavior

next-intl locale prefix behavior conflicts with SXA redirects' isLanguagePreserved switch - the latter switch overrides outcome, regardless of the languagePrefix value set for next-intl. This PR attempts to make the redirect results more predictable and configurable by renaming and reusing the localeInPath setting.

languagePrefix in next-intl	appLanguagePrefix	Result
'as-needed'	undefined	Content SDK behavior - isLanguagePreserved overrides next-intl behavior and applies locale when true
'as-needed'	'as-needed'	next-intl behavior - locale prefix is never applied when locale is defaultLanguage
'always'	'always'	next-intl behavior - locale prefix always applied, regardless of isLanguagePreserved
'never'	'never'	next-intl behavior - locale prefix is never applied, regardless of isLanguagePreserved

Testing Details

• Unit Test Added
• Manual Test/Other (Please elaborate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[changeset-bot]

⚠️ No Changeset found

Latest commit: c1f3f22

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes changesets to release 2 packages

Name	Type
@sitecore-content-sdk/nextjs	Patch
create-content-sdk-app	Patch

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[github-actions]

📦 Package Size and Test Coverage Report

Package	Base Size	PR Size	Δ Change	Base Coverage	PR Coverage	Δ Change
analytics-core	69.05 KB	69.05 KB	✅ 0.00 KB	97.44%	97.44%	0.00%
angular	337.93 KB	337.93 KB	✅ 0.00 KB	93.85%	93.85%	0.00%
cli	61.06 KB	61.06 KB	✅ 0.00 KB	71.36%	71.36%	0.00%
content	481.96 KB	481.96 KB	✅ 0.00 KB	92.86%	92.86%	0.00%
core	122.38 KB	122.38 KB	✅ 0.00 KB	91.22%	91.22%	0.00%
create-content-sdk-app	525.12 KB	525.68 KB	🔺 +0.56 KB	96.47%	96.47%	0.00%
events	72.33 KB	72.33 KB	✅ 0.00 KB	97.97%	97.97%	0.00%
nextjs	543.01 KB	539.86 KB	🔻 -3.15 KB	91.49%	91.47%	-0.02%
personalize	64.01 KB	64.01 KB	✅ 0.00 KB	99.74%	99.74%	0.00%
react	237.10 KB	237.10 KB	✅ 0.00 KB	93.95%	93.95%	0.00%
search	8.25 KB	8.25 KB	✅ 0.00 KB	98.72%	98.72%	0.00%
Total	—	—	🔻 -2.59 KB	—	—	—

[illiakovalenko]

This solution looks even better to me - good proposal! 👍
I have one suggestion below, thinking about the future and keeping our approach library-agnostic.
If you’ve already checked this scenario, great. If not, I’d recommend double-checking it by testing these settings without LocaleProxy, following our documentation: https://doc.sitecore.com/sai/en/developers/content-sdk/20/DEFAULT/disable-multisite-and-locale-proxies.html

[illiakovalenko]

Please revisit my very first comment regarding the next-intl references in our docs. Also, please double-check the build failure.

[illiakovalenko]

Looks good to me!
Please see one minor comment below. Once that’s addressed, feel free to merge

[illiakovalenko]

In general, we’re kind of duplicating the changeset we added for the nextjs package here. Could we simplify it and just mention that we’ve started leveraging a new setting in our template(s)? create-content-sdk-aap doesn't really bring this feature