refactor(analytics): centralize Umami tracking via env vars and shared utility

Move Umami analytics from hardcoded script tags in app.html to
server-side injection via hooks.server.ts. Website IDs are now
managed centrally in .env.development and distributed via
generate-env.mjs as PUBLIC_UMAMI_WEBSITE_ID.

- Add @manacore/shared-utils/analytics-server with injectUmamiAnalytics()
- Add UMAMI_WEBSITE_ID_* for all 17 web apps to .env.development
- Add PUBLIC_UMAMI_WEBSITE_ID mapping in generate-env.mjs for all web apps
- Update 10 existing hooks.server.ts to use shared utility
- Create 7 new hooks.server.ts (picture, planta, presi, photos, clock,
  questions, manadeck)
- Remove hardcoded Umami scripts from all 17 app.html files
- Add missing Umami tracking to Mukke and Questions
- Add shared-utils dependency to 6 web apps that lacked it
- Update ANALYTICS.md with architecture docs and "add new app" guide

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/shared-utils/package.json

@@ -6,7 +6,9 @@
 	"main": "./src/index.ts",
 	"types": "./src/index.ts",
 	"exports": {
-		".": "./src/index.ts"
+		".": "./src/index.ts",
+		"./analytics": "./src/analytics.ts",
+		"./analytics-server": "./src/analytics-server.ts"
 	},
 	"scripts": {
 		"type-check": "tsc --noEmit",