release: v3.3.1

Bumps version across pyproject.toml, mempalace/version.py, README badge,
and uv.lock. Finalizes the 3.3.0 CHANGELOG section (was still labeled
'Unreleased') and adds a 3.3.1 section covering the multi-language
entity-detection infra and the five new locales landed since 2026-04-13.

Highlights:
- Multi-language entity detection infra (#911) + script-aware word
  boundaries for combining-mark scripts (#932) + BCP 47 case-insensitive
  locale resolution (#928) + i18n patterns wired into miner/palace/
  entity_registry (#931)
- Five new fully-supported locales: pt-br (#156), ru (#760), it (#907),
  hi (#773), id (#778)
- UTF-8 encoding fix on read_text() calls for non-UTF-8 Windows locales
  (#946)
- KnowledgeGraph lock correctness (#884, #887)
- Various smaller fixes and improvements

uv.lock

@@ -1208,7 +1208,7 @@ wheels = [
 
 [[package]]
 name = "mempalace"
-version = "3.3.0"
+version = "3.3.1"
 source = { editable = "." }
 dependencies = [
     { name = "chromadb" },