Testing: Stabilized test suite and achieved 93% total coverage.

- Fixed CLI tests by patching local imports at source (psutil, os, Path).
- Fixed Collector tests by globalizing docker.from_env mock.
- Stabilized SSE stream tests via AsyncMock and immediate generator termination to prevent hangs.
- Achieved >80% coverage on CLI (84%), Collector (97%), and DB Repository (100%).
- Implemented SMTP Relay service tests (100%).

.gitignore

@@ -20,3 +20,5 @@ windows1
 decnet.json
 .env
 .env.local
+.coverage
+.hypothesis/