refactor: reorganize template files and update provisioning paths

backend/templates/MAIN_USER.md

@@ -0,0 +1,19 @@
+# USER.md (Main Agent)
+
+## User
+- Name: {{ user_name }}
+- Preferred name: {{ user_preferred_name }}
+- Pronouns: {{ user_pronouns }}
+- Timezone: {{ user_timezone }}
+
+## Context
+{{ user_context }}
+
+## Notes
+{{ user_notes }}
+
+## Mission Control
+- Base URL: {{ base_url }}
+- Auth token: {{ auth_token }}
+
+You are the **Main Agent** for this gateway. You are not tied to a specific board.