fix: address i18n review issues from PR #718

Three issues flagged by bensig on the i18n PR before merge:

1. ko.json: status_drawers used {drawers} instead of {count}, causing
   the Korean UI to show the raw template string instead of the actual
   drawer count.  All other 7 languages use {count}.

2. Test file was shipped inside the package at mempalace/i18n/test_i18n.py
   with a sys.path.insert hack.  Moved to tests/test_i18n.py per the
   project convention in AGENTS.md.

3. Dialect.from_config() passed lang=config.get("lang") which defaults
   to None, causing __init__ to inherit whatever language was loaded
   earlier via module-level state.  Now defaults to "en" explicitly so
   from_config is deterministic regardless of prior load_lang() calls.

Added two regression tests for the ko.json fix and the state leak.

tests/test_i18n.py

@@ -0,0 +1,86 @@
+"""Smoke tests for i18n dictionaries + Dialect integration."""
+
+from mempalace.i18n import load_lang, t, available_languages
+from mempalace.dialect import Dialect
+
+
+def test_all_languages_load():
+    """Every JSON file loads without error and has required keys."""
+    required_sections = ["terms", "cli", "aaak"]
+    required_terms = ["palace", "wing", "closet", "drawer"]
+
+    langs = available_languages()
+    assert len(langs) >= 7, f"Expected 7+ languages, got {len(langs)}"
+
+    for lang in langs:
+        strings = load_lang(lang)
+        for section in required_sections:
+            assert section in strings, f"{lang}: missing section '{section}'"
+        for term in required_terms:
+            assert term in strings["terms"], f"{lang}: missing term '{term}'"
+            assert len(strings["terms"][term]) > 0, f"{lang}: empty term '{term}'"
+        assert "instruction" in strings["aaak"], f"{lang}: missing aaak.instruction"
+
+    print(f"  PASS: {len(langs)} languages load correctly")
+
+
+def test_interpolation():
+    """String interpolation works for all languages."""
+    for lang in available_languages():
+        load_lang(lang)
+        result = t("cli.mine_complete", closets=5, drawers=100)
+        assert "5" in result, f"{lang}: closets count missing from mine_complete"
+        assert "100" in result, f"{lang}: drawers count missing from mine_complete"
+
+    print("  PASS: interpolation works for all languages")
+
+
+def test_dialect_loads_lang():
+    """Dialect class picks up the language instruction."""
+    for lang in available_languages():
+        d = Dialect(lang=lang)
+        assert d.lang == lang, f"Expected lang={lang}, got {d.lang}"
+        assert len(d.aaak_instruction) > 10, f"{lang}: AAAK instruction too short"
+
+    print("  PASS: Dialect loads language instruction for all languages")
+
+
+def test_dialect_compress_samples():
+    """Compress sample text in different languages, verify output isn't empty."""
+    samples = {
+        "en": "We decided to migrate from SQLite to PostgreSQL for better concurrent writes. Ben approved the PR yesterday.",
+        "fr": "Nous avons décidé de migrer de SQLite vers PostgreSQL pour une meilleure écriture concurrente. Ben a approuvé le PR hier.",
+        "ko": "더 나은 동시 쓰기를 위해 SQLite에서 PostgreSQL로 마이그레이션하기로 했습니다. 벤이 어제 PR을 승인했습니다.",
+        "ja": "同時書き込みの改善のため、SQLiteからPostgreSQLに移行することを決定しました。ベンが昨日PRを承認しました。",
+        "es": "Decidimos migrar de SQLite a PostgreSQL para mejor escritura concurrente. Ben aprobó el PR ayer.",
+        "de": "Wir haben beschlossen, von SQLite auf PostgreSQL zu migrieren für bessere gleichzeitige Schreibvorgänge. Ben hat den PR gestern genehmigt.",
+        "zh-CN": "我们决定从SQLite迁移到PostgreSQL以获得更好的并发写入。Ben昨天批准了PR。",
+    }
+
+    for lang, text in samples.items():
+        d = Dialect(lang=lang)
+        compressed = d.compress(text)
+        assert len(compressed) > 0, f"{lang}: compression returned empty"
+        assert len(compressed) < len(text) * 2, f"{lang}: compression expanded text"
+        print(f"    {lang}: {len(text)} chars → {len(compressed)} chars")
+        print(f"         {compressed[:80]}")
+
+    print("  PASS: compression works for all sample languages")
+
+
+def test_korean_status_drawers_uses_count():
+    """ko.json status_drawers must use {count}, not {drawers}."""
+    load_lang("ko")
+    result = t("cli.status_drawers", count=42)
+    assert "42" in result, f"Expected '42' in '{result}' -- count variable not interpolated"
+
+
+def test_from_config_defaults_to_english(tmp_path):
+    """Dialect.from_config without a lang key must not inherit module-level state."""
+    load_lang("ko")  # pollute module-level _current_lang
+
+    config_path = tmp_path / "config.json"
+    config_path.write_text('{"entities": {}}')
+
+    d = Dialect.from_config(str(config_path))
+    assert d.lang == "en", f"Expected 'en', got '{d.lang}' -- state leak from prior load_lang"