add ru locale to cli

Makefile

@@ -1,4 +1,11 @@
-.PHONY: all client server cli test clean
+.PHONY: all client server cli test clean i18n-extract i18n-init i18n-update i18n-compile
+
+# CLI localization (nexus-cli strings only; daemon/server logs stay in English).
+LOCALE_DIR := src/nexus_sync/locale
+POT := $(LOCALE_DIR)/nexus.pot
+LANG ?= ru
+# PyInstaller --add-data separator is ':' on Unix, ';' on Windows.
+LOCALE_DATA := $(LOCALE_DIR):nexus_sync/locale
 
 all: client server cli
 
@@ -8,8 +15,25 @@ client:
 server:
 	pyinstaller --onefile src/nexus_sync/server/__main__.py --name nexus-sync-server
 
-cli:
-	pyinstaller --onefile src/nexus_sync/cli/__main__.py --name nexus-cli
+cli: i18n-compile
+	pyinstaller --onefile src/nexus_sync/cli/__main__.py --name nexus-cli \
+		--add-data "$(LOCALE_DATA)"
+
+# Rebuild the message template from strings wrapped in _()/gettext()/ngettext().
+i18n-extract:
+	pybabel extract -F babel.cfg -k _ -o $(POT) src
+
+# Create a catalog for a new language, e.g. `make i18n-init LANG=de`.
+i18n-init: i18n-extract
+	pybabel init -i $(POT) -d $(LOCALE_DIR) -D nexus -l $(LANG)
+
+# Merge new/changed strings into existing catalogs.
+i18n-update: i18n-extract
+	pybabel update -i $(POT) -d $(LOCALE_DIR) -D nexus
+
+# Compile .po catalogs to the .mo files bundled with nexus-cli.
+i18n-compile:
+	pybabel compile -d $(LOCALE_DIR) -D nexus
 
 test:
 	pytest