refactor: restructure API, deduplicate code, expand test coverage

- Extract shared DeferClose helper, removing 14 duplicate copies
- Rename PlayWright-prefixed types to cleaner names (BrowserOptions,
  BrowserSelection, NewBrowser, etc.)
- Rename fields: ServerAddress, RequireServer (was DontLaunchOnConnectFailure)
- Extract shared initBrowser/mergeOptions into browser_init.go,
  deduplicating ~120 lines between NewBrowser and NewInteractiveBrowser
- Remove unused locator field from document struct
- Add tests for all previously untested packages (archive, aislegopher,
  wegmans, useragents, powerball) and expand existing test suites
- Add MIGRATION.md documenting all breaking API changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sites/duckduckgo/cmd/duckduckgo/main.go

@@ -3,12 +3,13 @@ package main
 import (
 	"context"
 	"fmt"
-	"github.com/urfave/cli/v3"
-	"io"
 	"os"
 	"strings"
 	"time"
 
+	"github.com/urfave/cli/v3"
+
+	"gitea.stevedudenhoeffer.com/steve/go-extractor"
 	"gitea.stevedudenhoeffer.com/steve/go-extractor/cmd/browser/pkg/browser"
 	"gitea.stevedudenhoeffer.com/steve/go-extractor/sites/duckduckgo"
 )
@@ -49,12 +50,6 @@ func (f DuckDuckGoFlags) ToConfig(cmd *cli.Command) (duckduckgo.Config, error) {
 	return res, nil
 }
 
-func deferClose(cl io.Closer) {
-	if cl != nil {
-		_ = cl.Close()
-	}
-}
-
 func main() {
 	var flags []cli.Flag
 
@@ -78,7 +73,7 @@ func main() {
 			}
 
 			b, err := browser.FromCommand(ctx, command)
-			defer deferClose(b)
+			defer extractor.DeferClose(b)
 
 			if err != nil {
 				return fmt.Errorf("failed to create browser: %w", err)
@@ -89,7 +84,7 @@ func main() {
 				return fmt.Errorf("failed to open search: %w", err)
 			}
 
-			defer deferClose(search)
+			defer extractor.DeferClose(search)
 
 			res := search.GetResults()
 			fmt.Println("Results:", res)