Rename module to sneak.berlin/go/x and rework bip39wordlist

Move to Go 1.26, embed the wordlist from english.txt, add
ValidateWordlist, NormalizeWordlist, and GenerateMnemonic with tests,
and remove the old root-level CLI that used the previous module path.

pkg/bip39wordlist/wordlist_test.go

@@ -0,0 +1,45 @@
+package bip39wordlist_test
+
+import (
+	"slices"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tyler-smith/go-bip39/wordlists"
+
+	"sneak.berlin/go/x/pkg/bip39wordlist"
+)
+
+func TestWordlistEnglishShape(t *testing.T) {
+	t.Parallel()
+
+	wordlist := bip39wordlist.WordlistEnglish
+
+	assert.Len(t, wordlist, bip39wordlist.WordlistSize)
+	assert.Equal(t, "abandon", wordlist[0])
+	assert.Equal(t, "zoo", wordlist[len(wordlist)-1])
+	assert.True(t, slices.IsSorted(wordlist), "wordlist must be sorted")
+}
+
+func TestWordlistEnglishMatchesReferenceImplementation(t *testing.T) {
+	t.Parallel()
+
+	assert.Equal(t, wordlists.English, bip39wordlist.WordlistEnglish)
+}
+
+func TestWordlistIsEnglish(t *testing.T) {
+	t.Parallel()
+
+	assert.Equal(t, bip39wordlist.WordlistEnglish, bip39wordlist.Wordlist)
+}
+
+func TestContains(t *testing.T) {
+	t.Parallel()
+
+	assert.True(t, bip39wordlist.Contains("abandon"))
+	assert.True(t, bip39wordlist.Contains("zoo"))
+	assert.True(t, bip39wordlist.Contains("legal"))
+	assert.False(t, bip39wordlist.Contains("Abandon"), "lookup is case sensitive")
+	assert.False(t, bip39wordlist.Contains("notaword"))
+	assert.False(t, bip39wordlist.Contains(""))
+}