🔧 chore: create @manacore/shared-nestjs-setup and migrate 8 backends

- Create shared package with bootstrapApp(), configureCors(), configureValidation()
- Migrate: chat, calendar, contacts, zitare, clock, planta, presi, nutriphi
- Skip complex backends: manadeck, picture, todo, skilltree, questions, storage

Savings: ~280 LOC (8 backends × 35 LOC each)

packages/shared-nestjs-setup/package.json

@@ -0,0 +1,25 @@
+{
+	"name": "@manacore/shared-nestjs-setup",
+	"version": "1.0.0",
+	"description": "Shared NestJS bootstrap utilities for ManaCore backends",
+	"main": "./src/index.ts",
+	"types": "./src/index.ts",
+	"exports": {
+		".": "./src/index.ts"
+	},
+	"scripts": {
+		"build": "tsc",
+		"type-check": "tsc --noEmit"
+	},
+	"dependencies": {
+		"@nestjs/common": "^10.0.0 || ^11.0.0",
+		"@nestjs/core": "^10.0.0 || ^11.0.0"
+	},
+	"devDependencies": {
+		"typescript": "^5.0.0"
+	},
+	"peerDependencies": {
+		"@nestjs/common": "^10.0.0 || ^11.0.0",
+		"@nestjs/core": "^10.0.0 || ^11.0.0"
+	}
+}