fix(agent): replace List.of() with Collections.emptyList() for Java 8 compatibility

[Copilot]

Addresses Java 9 incompatibility in AgentManifestLibs where List.of() was used despite project targeting Java 8.

Changes

• Replace List.of() calls with Collections.emptyList() in AgentManifestLibs.resolveFromManifest()
• Add Collections import

// Before (Java 9+)
return new ResolvedLibs(List.of(), List.of());

// After (Java 8 compatible)
return new ResolvedLibs(Collections.emptyList(), Collections.emptyList());

This ensures the agent compiles and runs on Java 8 as specified in project build configuration.

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