Update README.md

Author: veryyynice

README.md

@@ -200,3 +200,15 @@ users = listUserAccounts()
 ```
 
 Run such code from the project root so that `config`, `db`, and `services` are on `PYTHONPATH`.
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+---
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+## Notes & Limitations
+
+- **Device fingerprinting** — The `device_fingerprint` field is a caller-supplied string stored as-is. This project does not implement a real fingerprinting algorithm (e.g. hardware ID hashing, browser canvas fingerprinting). For local testing, pass any consistent unique string (e.g. `"my-macbook-001"`). In a production system, fingerprint generation would be handled by a native SDK on the device.
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+- **Approved locations** — The `locations` table acts as a whitelist of approved streaming locations. Adding locations to this table (the approval workflow) is out of scope for this project.
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+- **Login/logout tracking** — `trackUserLoginLogout` is stubbed; no `login_logs` table exists in the current schema.
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+- **Payments** — The `payments` table exists in the schema for data completeness but payment processing APIs are out of scope.