Add roadmap management feature with database schema and user management

- Implemented roadmap.php for displaying and managing roadmap items with filters for quarter and status.
- Created schema.sql to define the database structure for users, invites, daily plans, tasks, brainstorm sessions, brainstorm cards, roadmap items, and integrations.
- Developed users.php for admin panel to manage team members and invitations, including functionality to create and revoke invites.

.htaccess

@@ -0,0 +1,16 @@
+# Fociz Apache Configuratie
+DirectoryIndex index.php index.html
+
+# UTF-8 standaard
+AddDefaultCharset UTF-8
+
+# Blokkeer directe toegang tot SQL schema en configuratiebestanden
+<FilesMatch "^(schema\.sql|\.env|\.git.*)$">
+    Order allow,deny
+    Deny from all
+</FilesMatch>
+
+# PHP foutmeldingen in productie (kan uitgeschakeld worden indien gewenst)
+php_flag display_errors Off
+php_value error_reporting E_ALL
+