fix(ci): resolve ruff lint + format failures

- Remove unused `json` and `current_lang` imports from
  mempalace/i18n/test_i18n.py (F401)
- Reformat Dialect.__init__ signature in mempalace/dialect.py
  (ruff format collapses multi-line signature, adds blank line
  after lazy import)

Both auto-fixes from `ruff check --fix` / `ruff format`. No behavioral
changes.

mempalace/i18n/test_i18n.py

@@ -1,14 +1,13 @@
 #!/usr/bin/env python3
 """Quick smoke test for i18n dictionaries + Dialect integration."""
 
-import json
 import sys
 from pathlib import Path
 
 # Add parent to path so we can import mempalace
 sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
 
-from mempalace.i18n import load_lang, t, available_languages, current_lang
+from mempalace.i18n import load_lang, t, available_languages
 from mempalace.dialect import Dialect