feat: add Firefox extract methods and complete data model fields (#527)

* feat: add Firefox extract methods and complete data model fields

Firefox extract methods:
- extractPasswords: JSON + ASN1PBE decryption via decryptPBE helper
- extractCookies: SQLite, plaintext (no encryption), journalOff
- extractHistories: SQLite, visit count ASC sort (matches old behavior)
- extractDownloads: SQLite, moz_annos JOIN with JSON content parsing
- extractBookmarks: SQLite, moz_bookmarks JOIN moz_places
- extractExtensions: JSON, filter by location=app-profile
- extractLocalStorage: SQLite webappsstore2, reversed originKey parsing

Complete data model fields (union of Chromium and Firefox):
- CookieEntry: add HasExpire, IsPersistent
- DownloadEntry: add MimeType
- CreditCardEntry: add NickName, Address
- ExtensionEntry: add HomepageURL, Enabled

Update Chromium extractors to populate new fields:
- extract_cookie.go: fill HasExpire, IsPersistent
- extract_download.go: SELECT and fill mime_type
- extract_creditcard.go: SELECT nickname, billing_address_id
- extract_extension.go: fill HomepageURL, Enabled (state==1)

Tests:
- Full test coverage for all 7 Firefox extract functions
- Password test uses known ASN1PBE test vectors from crypto package
- Table-driven tests for parseOriginKey
- Updated Chromium tests for new fields

* fix: add COALESCE for nullable bookmark title in Firefox query

Firefox moz_bookmarks.title can be NULL (PR #500 fixed this in old code).
Add COALESCE to handle NULL gracefully in SQL instead of relying on
driver-specific NULL→string conversion behavior.

* fix: enable journalOff for all Firefox SQLite extractors and populate cookie flags

- Set journalOff=true for extract_history, extract_download, extract_bookmark
  (Firefox databases require PRAGMA journal_mode=off to avoid lock errors)
- Populate HasExpire and IsPersistent for Firefox cookies (derived from expiry>0)
- Add test assertions for HasExpire/IsPersistent in both Chromium and Firefox

browser/firefox/extract_extension_test.go

@@ -0,0 +1,62 @@
+package firefox
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExtractExtensions(t *testing.T) {
+	path := createTestJSON(t, "extensions.json", `{
+		"addons": [
+			{
+				"id": "ublock@gorhill.org",
+				"location": "app-profile",
+				"version": "1.52.0",
+				"active": true,
+				"defaultLocale": {
+					"name": "uBlock Origin",
+					"description": "An efficient blocker"
+				}
+			},
+			{
+				"id": "system@mozilla.org",
+				"location": "app-system-defaults",
+				"version": "1.0",
+				"defaultLocale": {"name": "System Addon"}
+			},
+			{
+				"id": "bitwarden@bitwarden.com",
+				"location": "app-profile",
+				"version": "2024.1.0",
+				"active": true,
+				"defaultLocale": {
+					"name": "Bitwarden",
+					"description": "Password manager"
+				}
+			}
+		]
+	}`)
+
+	got, err := extractExtensions(path)
+	require.NoError(t, err)
+	require.Len(t, got, 2) // system addon filtered out
+
+	ids := map[string]bool{}
+	for _, ext := range got {
+		ids[ext.ID] = true
+		assert.NotEmpty(t, ext.Name)
+		assert.NotEmpty(t, ext.Version)
+	}
+	assert.True(t, ids["ublock@gorhill.org"])
+	assert.True(t, ids["bitwarden@bitwarden.com"])
+	assert.False(t, ids["system@mozilla.org"])
+}
+
+func TestExtractExtensions_EmptyAddons(t *testing.T) {
+	path := createTestJSON(t, "extensions.json", `{"addons": []}`)
+	got, err := extractExtensions(path)
+	require.NoError(t, err)
+	assert.Empty(t, got)
+}