test: improve coverage across package

README.md

@@ -41,6 +41,29 @@ func main() {
 }
 ```
 
+## Testing
+
+Run all tests:
+
+```bash
+go test ./...
+```
+
+Run tests with coverage:
+
+```bash
+go test -cover ./...                              # per-package summary
+go test -coverprofile=coverage.out ./...          # full profile
+go tool cover -html=coverage.out -o coverage.html # HTML report
+```
+
+Run tests for a specific package:
+
+```bash
+go test -v ./analyzer/tcp/
+go test -v -run TestSSH ./analyzer/tcp/
+```
+
 Based on OpenGFW by apernet: https://github.com/apernet/OpenGFW
 
 ## LICENSE