[create-content-sdk-app] Fix static generation error by marking route handlers as force-dynamic

[MenKNas]

• This PR follows the Contribution Guide
• Changelog updated
• Upgrade guide entry added

Description / Motivation

Fix route handler static generation error

Fixed an issue where Next.js was attempting to statically generate route handlers that use request.headers, causing build failures with the error "Route couldn't be rendered statically because it used request.headers".

Solution:
Added export const dynamic = 'force-dynamic' to all route handlers that access request headers, cookies, or draftMode. This explicitly marks them as dynamic routes that must be rendered at request time.

Affected routes:

• Sitemap route handler
• Robots route handler
• Editing config route handler
• Editing render route handler

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)

[github-actions]

📦 Package Size and Test Coverage Report

Package	Base Size	PR Size	Δ Change	Base Coverage	PR Coverage	Δ Change
analytics-core	122.52 KB	122.52 KB	✅ 0.00 KB	100.00%	100.00%	0.00%
cli	58.68 KB	58.68 KB	✅ 0.00 KB	69.73%	69.73%	0.00%
core	505.17 KB	505.17 KB	✅ 0.00 KB	91.23%	91.23%	0.00%
create-content-sdk-app	243.34 KB	243.64 KB	🔺 +0.30 KB	96.22%	96.22%	0.00%
events	76.91 KB	76.91 KB	✅ 0.00 KB	98.40%	98.40%	0.00%
nextjs	427.50 KB	427.50 KB	✅ 0.00 KB	89.73%	89.73%	0.00%
personalize	63.45 KB	63.45 KB	✅ 0.00 KB	99.32%	99.32%	0.00%
react	289.13 KB	289.13 KB	✅ 0.00 KB	93.64%	93.64%	0.00%
search	6.40 KB	6.40 KB	✅ 0.00 KB	98.57%	98.57%	0.00%
Total	—	—	🔺 +0.30 KB	—	—	—