data(mobile): import sady36 market variants

[Seungpyo1007]

Summary

• import sady36/mobile-phones-specs market variants as unverified mobile records
• keep country/market, memory, network/model-number variants as separate records
• refresh public v1 smartphone/tablet list and detail snapshots

Imported data

• total added records: 23,450
• smartphones: 23,354
• tablets: 96
• years: 2015 31, 2016 119, 2017 371, 2018 4,081, 2019 4,633, 2020 4,372, 2021 4,022, 2022 4,705, 2023 1,116
• source: https://www.kaggle.com/datasets/sady36/mobile-phones-specs
• verification state: all imported records use verified: false

Verification

• python -m app.validate PASS
• python TechEngine\integrity_check.py data --strict PASS
• git diff --check origin/main...HEAD PASS
• cd site && npm.cmd run build PASS

Closes #1