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/httplog/proxy_test.go

@@ -331,7 +331,7 @@ func TestProxy_Start_PortInUse(t *testing.T) {
 	}
 	err := proxy1.Start()
 	require.NoError(t, err)
-	defer proxy1.Stop()
+	defer func() { _ = proxy1.Stop() }()
 
 	// Get the actual port
 	addr := proxy1.listener.Addr().(*net.TCPAddr)
@@ -353,9 +353,9 @@ func TestProxy_Start_PortInUse(t *testing.T) {
 // TestFlattenHeaders_EdgeCases tests header flattening edge cases
 func TestFlattenHeaders_EdgeCases(t *testing.T) {
 	tests := []struct {
-		name     string
 		headers  http.Header
 		expected map[string]string
+		name     string
 	}{
 		{
 			name:     "empty headers",