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/benchmark/runner.go

@@ -16,15 +16,15 @@ type ProgressCallback func(completed, total int)
 
 // Config holds the benchmark configuration
 type Config struct {
-	URL              string            // Target URL
-	Method           string            // HTTP method
-	Headers          map[string]string // Custom headers
-	Body             []byte            // Request body
-	Concurrency      int               // Number of concurrent workers
-	Requests         int               // Total number of requests (0 = use duration)
-	Duration         time.Duration     // Duration to run (0 = use requests)
-	Timeout          time.Duration     // Request timeout
-	ProgressCallback ProgressCallback  // Optional callback for progress updates
+	Headers          map[string]string
+	ProgressCallback ProgressCallback
+	URL              string
+	Method           string
+	Body             []byte
+	Concurrency      int
+	Requests         int
+	Duration         time.Duration
+	Timeout          time.Duration
 }
 
 // Runner executes HTTP benchmarks