polhenarejos/pico-fido

AI Summary: On pico-fido v7.0, discoverable (resident) credentials are being silently overwritten if their `user.id` shares a common prefix with an existing credential. This faulty deduplication logic causes irreversible data loss, as only one credential per prefix chain (e.g., `raspi_1`, `raspi_12`, `raspi_123`) is retained instead of allocating new slots.