feat: migrate rendering to VirtualEntities 0.9.0

[twme-ai]

Summary

• replace the shaded EntityLib rendering backend with VirtualEntities v0.9.0
• use the released TextDisplayShapes 3.0.0 artifact from the official TWME Maven repository
• share one VirtualEntityManager and canonical VirtualViewer instances across selection shapes and labels
• close renderers and unregister PacketEvents listeners during plugin shutdown
• bump WorldEditDisplay to 2.5.0
• include the Java 17, api-version 1.19, and degenerate-line compatibility fixes from fix: support Paper 1.19.4 and skip degenerate render lines #61

This supersedes #61.

Compatibility

The final shaded Paper and Spigot artifacts contain 224 VirtualEntities classes and no EntityLib classes. All classes target Java 17 (class major 61).

• Paper: 21/21 stable versions passed from 1.19.4 through 26.2
• Spigot: 24/24 exact versions passed from 1.19.4 through 26.2
• 225/225 selection-shape cases passed across cuboid, cylinder, ellipsoid, polygon, and polyhedron
• each case required positive server-side retained entity counts and client-observed text_display packets
• all 45 server logs were clear of plugin enable errors, renderer errors, replay/watchdog failures, and class/API version errors

The released 3.0.0 packet-module classes are byte-for-byte identical to the pre-release commit used for the full version matrix.

Verification

• fresh Maven cache: mvn -B -U clean verify (Paper), 34/34 tests
• fresh Maven cache: mvn -B -U -P spigot clean verify, 34/34 tests
• Maven provenance confirms TextDisplayShapes from twme-releases and VirtualEntities from jitpack
• retained-render E2E verifies 72 reused lines with zero respawns/removals for unchanged geometry
• shared-label E2E verifies shapes and labels use the same client connection