Auto-suggest name for new Passkeys

- Use plain client data json everywhere
- Expose AAGUID and backed_up on Credentials
- Make attestation verifiers configurable
- Auto-suggest names for passkeys and show icons

db/migrate/20260219095815_add_aaguid_and_backed_up_to_identity_credentials.rb

@@ -0,0 +1,6 @@
+class AddAaguidAndBackedUpToIdentityCredentials < ActiveRecord::Migration[8.2]
+  def change
+    add_column :identity_credentials, :aaguid, :string
+    add_column :identity_credentials, :backed_up, :boolean
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.2].define(version: 2026_02_18_120000) do
+ActiveRecord::Schema[8.2].define(version: 2026_02_19_095815) do
   create_table "accesses", id: :uuid, charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.datetime "accessed_at"
     t.uuid "account_id", null: false
@@ -345,6 +345,8 @@ ActiveRecord::Schema[8.2].define(version: 2026_02_18_120000) do
   end
 
   create_table "identity_credentials", id: :uuid, charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.string "aaguid"
+    t.boolean "backed_up"
     t.datetime "created_at", null: false
     t.string "credential_id", null: false
     t.uuid "identity_id", null: false