fix: QA audit — lint cleanup, i18n fixes, module visibility, sidebar UX

- Fix 97 lint errors → 0 (unused imports, params, variables across 40+ files)
- Fix i18n key format: colon → dot notation for next-intl compatibility
- Add missing i18n keys (routes.application, routes.home, confirm)
- Fix module visibility: sidebar now respects per-account DB features
- Fix inject function: use dot-notation keys, add collapsed:true defaults
- Fix ConfirmDialog: use useTranslations instead of hardcoded German defaults
- Fix events page: replace placeholder 'Beschreibung' with proper description
- Fix Dockerfile: add NEXT_PUBLIC_CI ARG for Docker builds
- Collapse secondary sidebar sections by default for cleaner UX

apps/e2e/tests/module-builder.spec.ts

@@ -5,7 +5,7 @@ import { test, expect } from '@playwright/test';
 
 test.describe('Module Builder', () => {
   test('create module, add fields, insert record, query, update, soft-delete', async ({
-    page,
+    page: _page,
   }) => {
     // Login
     await page.goto('/auth/sign-in');
@@ -24,7 +24,7 @@ test.describe('Module Builder', () => {
 });
 
 test.describe('Cross-tenant isolation', () => {
-  test('tenant A cannot see tenant B data', async ({ page }) => {
+  test('tenant A cannot see tenant B data', async ({ page: _page }) => {
     // Login as tenant A user
     // Verify can see own modules
     // Verify cannot access tenant B module URL