Add read api

[kiki0518]

Type of changes

Feature

Purpose

Add read tracking API for users to mark Issue or Viewpoint replies as read.

Additional Information

• Create ReadEntity with a composite primary key (userId, objectId, objectType) to track read status.
• Support both POST to update and GET to retrieve read status.
• Add controller endpoints for Issue and Viewpoint types.
• Add three POST, three GET endpoints:
  • POST GET /api/read/issue/{id}
  • POST GET /api/read/viewpoint/{id}
  • POST GET /api/read/reply/{id}
• POST endpoints is for setting readStatus of that object to "TRUE"
• Use @LastModifiedDate to automatically update the updatedAt field.
• Avoid using @mapsid to allow nullable foreign keys for issue and viewpoint.
• Optimize query performance with repository methods and planned indexing on userId and objectId.
  Create ReadEntity with a composite primary key (userId, objectId, objectType) to track read status.

[github-actions]

🦙 MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
✅ JAVA	checkstyle	31		0	0	4.21s
✅ REPOSITORY	dustilock	yes		no	no	0.45s
✅ REPOSITORY	gitleaks	yes		no	no	2.05s
✅ REPOSITORY	git_diff	yes		no	no	0.01s
✅ REPOSITORY	grype	yes		no	no	27.01s
✅ REPOSITORY	secretlint	yes		no	no	2.3s
✅ REPOSITORY	syft	yes		no	no	2.76s
✅ REPOSITORY	trivy-sbom	yes		no	no	0.65s
✅ REPOSITORY	trufflehog	yes		no	no	5.21s

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