feat(ui): add identity management for tenants and users

* Implement tenant and user creation in IdentityPage
* Add API calls for managing tenants and users
* Introduce tenant-scoped API requests
* Update sidebar to include identity navigation
* Create BooleanStatusBadge component for key status

schema/files.dbml

@@ -3,7 +3,7 @@ Table stored_files {
   guid uuid [unique, not null, default: `gen_random_uuid()`]
   thought_id bigint [ref: > thoughts.id]
   project_id bigint [ref: > projects.id]
-  tenant_key text
+  tenant_id text [ref: > tenants.id]
   name text [not null]
   media_type text [not null]
   kind text [not null, default: 'file']
@@ -17,7 +17,7 @@ Table stored_files {
   indexes {
     thought_id
     project_id
-    tenant_key
+    tenant_id
     sha256
   }
 }