refactor!: a lot of stuff

README.md

@@ -16,7 +16,7 @@ Response shape:
     "used_percent": 0,
     "remaining_percent": 100,
     "exhausted": false,
-    "needs_refresh": false
+    "needs_prepare": false
   },
   "usage": {
     "primary_window": {
@@ -54,10 +54,8 @@ Behavior:
 
 ## Startup Behavior
 
-On startup, service:
-
-1. Ensures active token exists and is usable.
-2. Ensures `next_account` is prepared for ChatGPT.
+On startup, service ensures active token exists and is usable.
+Standby preparation runs through provider lifecycle hooks/background trigger when needed.
 
 ## Data Files
 
@@ -70,6 +68,14 @@ On startup, service:
 PYTHONPATH=./src python src/server.py
 ```
 
+## Unit Tests
+
+The project has unit tests only (no integration/network tests).
+
+```bash
+pytest -q
+```
+
 ## Docker Notes
 
 - Dockerfile sets `DATA_DIR=/data`.