Factory Commissioning Follow-up

The factory flash flow currently erases the NVS partition before writing firmware so previously commissioned units can be recommissioned. The current Leaf partition table uses the standard Arduino ESP32 NVS range:

Partition: nvs
Type/subtype: data, nvs
Offset: 0x9000
Size: 0x5000 (20K)

This was verified against both the configured default_8MB.csv partition table and the generated leaf_3_2_6_release partitions.bin artifact.

Future work:

Replace the factory_interface hardcoded NVS erase range with partition-table-derived values.
Prefer parsing the configured/generated partition table and erasing the partition named nvs.
Keep the current hardcoded range acceptable while Leaf continues to use the standard default_8MB.csv layout.