fix: use i18n candidate patterns for entity extraction in miner and palace

entity_detector.py was refactored in #911 to load candidate patterns
from i18n locale JSON files, supporting non-Latin scripts (Cyrillic,
accented Latin, etc.). But three other code paths still hardcoded the
ASCII-only regex [A-Z][a-z]{2,}, silently missing non-Latin entity
names in metadata tagging, closet indexing, and registry lookups.

Replace the hardcoded regex with a shared _candidate_entity_words()
helper that reuses the same i18n candidate_patterns as entity_detector.

mempalace/entity_registry.py

@@ -656,7 +656,9 @@ class EntityRegistry:
         Find capitalized words in query that aren't in registry or common words.
         These are candidates for Wikipedia research.
         """
-        candidates = re.findall(r"\b[A-Z][a-z]{2,15}\b", query)
+        from .palace import _candidate_entity_words
+
+        candidates = _candidate_entity_words(query)
         unknown = []
         for word in set(candidates):
             if word.lower() in COMMON_ENGLISH_WORDS: