Remove platform tenancy from SXCHNGE customer BFF (#34)

backend/README.md

@@ -1,7 +1,7 @@
 # SXCHNGE BFF
 
 A locally owned copy of Sendico's reusable BFF runtime, authentication/session
-stack and account service. See [provenance](PROVENANCE.md) and the
+stack and customer account service. See [provenance](PROVENANCE.md) and the
 [architecture and public API plan](../docs/architecture/bff.md).
 
 SXCHNGE owns its customers and authentication. SXCHNGE itself is one organization
@@ -19,21 +19,16 @@ Copy `config.example.yml` to an untracked `config.yml`. Set:
 - `SXCHNGE_API_PROTOCOL`: `http` locally, `https` in deployment.
 - `SXCHNGE_API_ENDPOINT`: `/api/v1`.
 
-Seed the local policy descriptions before first startup (requires `mongosh`):
-
-```sh
-mongosh "$SXCHNGE_MONGO_URI" --file backend/scripts/seed-policies.js
-```
-
-The seed is repeatable and creates only the three local built-in policy
-descriptions required by the copied runtime. It grants no role permissions.
+The runtime starts against an empty SXCHNGE database and creates its indexes.
+No organization, role, policy or seed is required.
 Run `make run-backend` from the repository root. The copied CLI accepts
 `-config.file`, `-version` and `-debug`. Configure exact browser origins in YAML;
 secure refresh cookies require HTTPS for browser session testing.
 
 The runtime mounts `/api/v1/health` and the copied account login, API login,
 refresh, rotation and logout handlers. Customer/client records must exist in the
-local database. The account service is initialized locally; signup/profile and
+local database. The account service creates customers and activation tokens
+atomically, and deletes customers with session revocation. It is initialized locally; signup/profile and
 verification-delivery/completion routes are the next wiring work. This is a
 bootstrap, not a finished authentication deployment. No Sendico calls are made.