[Duplicate] Feature/project management endpoints 63

[LinseCed]

Important

Duplicate of #112

Related issue

Closes #63

Short summary

Implements paginated and filterable artifact retrieval through separate administrative and project-scoped endpoints.

The original global artifact endpoint was split to keep system-wide administrative access separate from regular project-level access:

• Added GET /api/v1/admin/artifacts for administrators to retrieve artifacts across all projects.
• Added GET /api/v1/projects/{projectId}/artifacts for users to retrieve artifacts belonging to a project they can access.
• Added pagination with configurable page and size parameters.
• Added filtering across artifact metadata such as name, status, type, source and owner.
• Added project access validation for the project-scoped endpoint.
• Added response pagination metadata, including total items, total pages and navigation flags.

Checks

• I verified the code makes sense intuitively
• The PR changes affect only this issue, no unrelated/unwanted code changes to other modules/code segments
• CI runs (./gradlew clean build, Keycloak)
• New business logic is unit tested, including WebMvcTest for API controllers
• The new functionality is tested manually

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Note: this branch (feature/project-management-endpoints-63-dev-backup) stacks on top of #124 (the dev-backup duplicate of #110, which this PR's original branch also depended on), since #112 built directly on #110's branch and had dev merged into it multiple times to resolve real conflicts. This is a clean cherry-pick of just #112's own net diff on top of #124's branch. Until #124 merges into dev-backup, this diff will show both PRs' combined changes; it will shrink to just #112's own changes once #124 lands, mirroring how the original PRs looked before #110 merged into dev.