style: Extract UI constants and refactor main view rendering (#30)

- [x] Add golangci-lint configuration with gocritic ifElseChain disabled
- [x] Rename error variables to avoid shadowing (createErr, watcherErr, watchErr, etc.)
- [x] Replace `interface{}` with `any` type alias throughout codebase
- [x] Add package-level documentation comments to all internal packages
- [x] Reorder struct fields alphabetically for consistency
- [x] Extract UI constants (terminal dimensions, column widths, colors) to constants.go
- [x] Refactor BubbleTeaUI main view rendering into smaller helper functions
- [x] Simplify nested conditionals and improve code clarity
- [x] Add `isForwardDisabled()` helper method to BubbleTeaUI
- [x] Update file permissions from 0644 to 0600 in config tests
- [x] Add `#nosec` comments and error suppression where appropriate
- [x] Improve test table struct field ordering for readability
- [x] Fix resource parsing in AddForward using strings.SplitN
- [x] Add comprehensive tests for new UI helper functions and constants

internal/healthcheck/checker_test.go

@@ -88,9 +88,9 @@ func (s *HealthCheckTestSuite) TestRegisterAndUnregister() {
 func (s *HealthCheckTestSuite) TestTCPDialMethod() {
 	tests := []struct {
 		name           string
-		setupPort      bool
 		expectedStatus Status
 		description    string
+		setupPort      bool
 	}{
 		{
 			name:           "port available - healthy",
@@ -109,10 +109,9 @@ func (s *HealthCheckTestSuite) TestTCPDialMethod() {
 	for _, tt := range tests {
 		s.Run(tt.name, func() {
 			var testPort int
-			var testListener net.Listener
 
 			if tt.setupPort {
-				// Use the existing listener
+				// Use the existing listener from suite setup
 				testPort = s.port
 			} else {
 				// Use a port that's not listening
@@ -143,10 +142,6 @@ func (s *HealthCheckTestSuite) TestTCPDialMethod() {
 			status, exists := checker.GetStatus("test-forward")
 			assert.True(s.T(), exists)
 			assert.Equal(s.T(), tt.expectedStatus, status, tt.description)
-
-			if testListener != nil {
-				testListener.Close()
-			}
 		})
 	}
 }
@@ -201,7 +196,7 @@ func (s *HealthCheckTestSuite) TestDataTransferMethod() {
 						}
 						switch tt.serverBehavior {
 						case "banner":
-							conn.Write([]byte("220 Welcome\r\n"))
+							_, _ = conn.Write([]byte("220 Welcome\r\n"))
 							time.Sleep(50 * time.Millisecond)
 							conn.Close()
 						case "close":