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/aislegopher/aislegopher.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io"
 	"net/url"
 	"strconv"
 	"strings"
@@ -27,11 +26,6 @@ type Item struct {
 	Price float64
 }
 
-func deferClose(cl io.Closer) {
-	if cl != nil {
-		_ = cl.Close()
-	}
-}
 func GetItemFromURL(ctx context.Context, b extractor.Browser, u *url.URL) (Item, error) {
 	return DefaultConfig.GetItemFromURL(ctx, b, u)
 }
@@ -57,7 +51,7 @@ func (c Config) GetItemFromURL(ctx context.Context, b extractor.Browser, u *url.
 	res.ID, _ = strconv.Atoi(a[3])
 
 	doc, err := b.Open(ctx, u.String(), extractor.OpenPageOptions{})
-	defer deferClose(doc)
+	defer extractor.DeferClose(doc)
 	if err != nil {
 		return res, fmt.Errorf("failed to open page: %w", err)
 	}

sites/aislegopher/aislegopher_test.go

@@ -0,0 +1,39 @@
+package aislegopher
+
+import (
+	"context"
+	"net/url"
+	"testing"
+)
+
+func TestGetItemFromURL_InvalidHost(t *testing.T) {
+	u, _ := url.Parse("https://example.com/p/slug/123")
+	_, err := GetItemFromURL(context.Background(), nil, u)
+	if err != ErrInvalidURL {
+		t.Errorf("expected ErrInvalidURL, got %v", err)
+	}
+}
+
+func TestGetItemFromURL_InvalidPath_NoP(t *testing.T) {
+	u, _ := url.Parse("https://aislegopher.com/x/slug/123")
+	_, err := GetItemFromURL(context.Background(), nil, u)
+	if err != ErrInvalidURL {
+		t.Errorf("expected ErrInvalidURL, got %v", err)
+	}
+}
+
+func TestGetItemFromURL_InvalidPath_TooShort(t *testing.T) {
+	u, _ := url.Parse("https://aislegopher.com/p/slug")
+	_, err := GetItemFromURL(context.Background(), nil, u)
+	if err != ErrInvalidURL {
+		t.Errorf("expected ErrInvalidURL, got %v", err)
+	}
+}
+
+func TestGetItemFromURL_InvalidPath_TooLong(t *testing.T) {
+	u, _ := url.Parse("https://aislegopher.com/p/slug/123/extra")
+	_, err := GetItemFromURL(context.Background(), nil, u)
+	if err != ErrInvalidURL {
+		t.Errorf("expected ErrInvalidURL, got %v", err)
+	}
+}

sites/aislegopher/cmd/aislegopher/aislegopher.go

@@ -3,10 +3,10 @@ package main
 import (
 	"context"
 	"fmt"
-	"io"
 	"net/url"
 	"os"
 
+	"gitea.stevedudenhoeffer.com/steve/go-extractor"
 	"gitea.stevedudenhoeffer.com/steve/go-extractor/cmd/browser/pkg/browser"
 	"gitea.stevedudenhoeffer.com/steve/go-extractor/sites/aislegopher"
 	"github.com/urfave/cli/v3"
@@ -22,11 +22,6 @@ func (f AisleGopherFlags) ToConfig(_ *cli.Command) aislegopher.Config {
 	return res
 }
 
-func deferClose(cl io.Closer) {
-	if cl != nil {
-		_ = cl.Close()
-	}
-}
 func main() {
 	var flags []cli.Flag
 	flags = append(flags, browser.Flags...)
@@ -44,7 +39,7 @@ func main() {
 				return fmt.Errorf("failed to create browser: %w", err)
 			}
 
-			defer deferClose(b)
+			defer extractor.DeferClose(b)
 
 			arg := c.Args().First()