Add tests for Plex loader

[Teagan42]

Summary

• ensure load-data awaits delay between continuous runs
• add CLI tests covering --continuous, --delay, and error scenarios
• refactor CLI to invoke new async load_media wrapper

Testing

• pytest --cov=mcp_plex

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https://chatgpt.com/codex/tasks/task_e_68b3d18cf15c8328a626cad848d83387

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mcp_plex
loader.py	179	10	94%	32–34, 296, 299–302, 486, 492
server.py	52	2	96%	33–34
TOTAL	333	12	96%

Tests	Skipped	Failures	Errors	Time
11	0 💤	0 ❌	0 🔥	5.864s ⏱️