CELDEV-1351 Deploy Presentation REST API

[fpichler]

Summary

• deploy the new Presentation REST web overlay in celements-webapp
• consume celements-presentation-web versionlessly through the 7.3 BOM-managed dependency chain
• add a deployment contract test for the root Spring context and /api/* DispatcherServlet mapping

Requirements

• CELDEV-1351

Depends on

• CELDEV-1351 Extract Presentation REST reuse seams celements-core#423
• CELDEV-1351 Add Presentation REST API celements-features#108
• CELDEV-1351 Manage Presentation REST artifacts celements-parent-poms#147

Validation

• deployment test: 1 passed
• fully unskipped npm, TypeScript, Vite, Babel, overlay, and WAR build passed
• assembled WAR contains the 7.3 presentation component through BOM-managed resolution
• coordinated 7.3 core, feature, BOM, and web dependency chain passed
• Docker runtime startup and /api/v3/api-docs HTTP 200 verified
• anonymous controlled 404/400 responses verified
• git diff --check

Representative successful presentation and authenticated-preview requests still require suitable runtime fixture data.