✨ feat(matrix-bots): add i18n system and direct message fallback

- Add I18nService with per-user language preferences (de/en)
- Add !language/!sprache command to all 4 bots (todo, calendar, contacts, clock)
- Add fallback behavior: messages without commands create tasks/events/contacts/timers
- Improve clock bot duration parsing to accept bare numbers as minutes (e.g. "25" = 25min)
- Add support for more duration formats: "25 minuten", "1 stunde", etc.

Language preferences stored in SessionService, default configurable via BOT_DEFAULT_LANGUAGE env var.

packages/bot-services/package.json

@@ -38,6 +38,10 @@
 			"types": "./dist/credit/index.d.ts",
 			"default": "./dist/credit/index.js"
 		},
+		"./i18n": {
+			"types": "./dist/i18n/index.d.ts",
+			"default": "./dist/i18n/index.js"
+		},
 		"./nutrition": {
 			"types": "./dist/nutrition/index.d.ts",
 			"default": "./dist/nutrition/index.js"