fix: address functionality gaps identified in code review

- Wire up --config/-f flag to actually load custom config files
  - Move config loading to PersistentPreRunE in root.go
  - Simplify main.go to just call cmd.Execute()
  - Move Playwright init to web command's PreRunE/PostRunE

- Remove unused functions from cmd/web.go (~90 lines of dead code)
  - Remove writeSingleFile, writeMultipleFiles, generateDefaultFilename
  - Remove scrapeURL, extractAndConvertContent, testExtractAndConvertContent
  - Remove unused mock function from web_test.go

- Add OutputType validation to Config.Validate()
  - Only allow "single", "separate", or empty string
  - Add test cases for valid and invalid output types

main.go

@@ -2,40 +2,13 @@ package main
 
 import (
 	"fmt"
-	"log"
 	"os"
 
 	"github.com/tnypxl/rollup/cmd"
-	"github.com/tnypxl/rollup/internal/config"
-	"github.com/tnypxl/rollup/internal/scraper"
 )
 
 func main() {
-	// Check if the command is "help"
-	isHelpCommand := len(os.Args) > 1 && (os.Args[1] == "help" || os.Args[1] == "--help" || os.Args[1] == "-h")
-
-	var cfg *config.Config
-	var err error
-
-	if !isHelpCommand {
-		configPath := "rollup.yml"
-		cfg, err = config.Load(configPath)
-		if err != nil {
-			log.Printf("Warning: Failed to load configuration: %v", err)
-			// Continue execution without a config file
-		}
-
-		// Initialize the scraper logger with default verbosity (false)
-		scraper.SetupLogger(false)
-
-		err = scraper.InitPlaywright()
-		if err != nil {
-			log.Fatalf("Failed to initialize Playwright: %v", err)
-		}
-		defer scraper.ClosePlaywright()
-	}
-
-	if err := cmd.Execute(cfg); err != nil {
+	if err := cmd.Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}