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/k8s/portforward.go

@@ -49,16 +49,16 @@ func (pf *PortForwarder) SetDialTimeout(timeout time.Duration) {
 
 // ForwardRequest contains the parameters for a port-forward request.
 type ForwardRequest struct {
-	ContextName string // Kubernetes context name
-	Namespace   string // Namespace
-	Resource    string // Resource (pod/name or service/name)
-	Selector    string // Label selector (for pod resolution)
-	LocalPort   int    // Local port
-	RemotePort  int    // Remote port
+	Out         io.Writer
+	ErrOut      io.Writer
 	StopChan    chan struct{}
 	ReadyChan   chan struct{}
-	Out         io.Writer // Output writer for logs
-	ErrOut      io.Writer // Error output writer
+	ContextName string
+	Namespace   string
+	Resource    string
+	Selector    string
+	LocalPort   int
+	RemotePort  int
 }
 
 // Forward establishes a port-forward connection to a Kubernetes resource.