docs: align agent auth model and fix session test

docs/module-decomposition.md

@@ -102,9 +102,10 @@
 - хранение workspace-scoped operations и version snapshots;
 - хранение workspace-scoped secrets и secret versions;
 - хранение agents и agent versions;
+- хранение agent keys и выданных agent tokens;
 - хранение stream sessions и async jobs;
 - auth profiles;
-- platform API keys;
+- platform client credentials;
 - logs и usage aggregates;
 - metadata по sample artifacts и descriptors.
 
@@ -138,7 +139,8 @@
 - `operations`
 - `auth_profiles`
 - `agents`
-- `platform_api_keys`
+- `agent_keys`
+- `platform_clients`
 - `logs`
 - `usage`
 - `streaming`