Fold watch-only into Import; support xprv spending import

Home screen is back to two tabs (Create / Import). The Import box now
takes a recovery phrase, an xpub/zpub, or an xprv/zprv:
- mnemonic → full wallet (as before)
- xpub/zpub → watch-only (view/receive, no Send)
- xprv/zprv → full spending wallet with no mnemonic. parseExtendedKey
  classifies + normalizes version bytes; account() derives the BIP84
  path from a master xprv (depth 0) or uses an account-level xprv as-is;
  signing works (only watch-only blocks it). Vault persists xprv accounts
  too; Settings shows an "Imported key" note instead of a recovery card
  and hides Nostr sync (no seed). Public-key export still works.

Note: a seed phrase cannot be derived from an xprv (one-way KDF), so an
xprv wallet has no recovery words by design. New strings in all 19 locales.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/locales/zh.json b/src/locales/zh.json
index 72bc340..35bd3a5 100644
--- a/src/locales/zh.json
+++ b/src/locales/zh.json
@@ -176,7 +176,6 @@
   "accounts": "账户",
   "addWallet": "添加钱包",
   "lockAll": "全部锁定",
-  "remove": "移除",
   "watchOnly": "仅查看",
   "watchOnlyTag": "仅查看",
   "watchOnlyAdd": "添加仅查看",
@@ -206,5 +205,10 @@
   "unlockSavedDesc": "输入你的密码以打开此设备上保存的钱包。",
   "unlock": "解锁",
   "useAnotherWallet": "使用其他钱包",
-  "save": "保存"
+  "save": "保存",
+  "importLabel": "恢复短语或密钥",
+  "importPlaceholder": "你的 12 或 24 个单词，或 xpub / xprv",
+  "invalidImport": "这不是有效的恢复短语、xpub 或 xprv。",
+  "importedKey": "导入的密钥",
+  "importedKeyNote": "该钱包是从扩展私钥导入的，因此没有恢复短语。请备份该密钥本身以保留钱包。"
 }
\ No newline at end of file