ci: add golangci-lint config and fix formatting

- Add .golangci.yml with minimal linters (govet, ineffassign)
- Run gofmt -s and goimports on all files to fix formatting
- Disable fieldalignment and copylocks checks in govet

internal/database/mysql.go

@@ -387,7 +387,7 @@ func (m *MySQL) buildDSN() string {
 			"/tmp/mysql.sock",
 			"/var/lib/mysql/mysql.sock",
 		}
-		
+
 		// Use the first available socket path, fallback to TCP if none found
 		socketFound := false
 		for _, socketPath := range socketPaths {
@@ -397,7 +397,7 @@ func (m *MySQL) buildDSN() string {
 				break
 			}
 		}
-		
+
 		// If no socket found, use TCP localhost
 		if !socketFound {
 			dsn += "tcp(localhost:" + strconv.Itoa(m.cfg.Port) + ")"