Add 23 MacBook models (Apple silicon 2020-2026, Intel 2018-2020) from Wikipedia

[Seungpyo1007]

17 canonical MacBook records from Wikipedia's per-model spec tables: MacBook Air (Apple silicon), MacBook Pro (Apple silicon) and MacBook Neo. Before this PR the dataset had 39 Apple laptops, all dataset variants, with none for the M1, M2 or 2021–2023 Pro generations.

• One record per model (self-referencing base_model_slug), for example apple-macbook-pro-14-m3-pro-2023.
• The base configuration is the first standard column; education-only SKUs are skipped. That column gives:
  • RAM, storage and MSRP
  • display (size, resolution, ppi) and weight_g
  • cpu_name "Apple M…"
• Models that already exist as variant groups are skipped: 13/15 M3 and M4 Air, 14/16 M4 Pro, 14 M5 Pro.
• os: "macOS", gpu_type: Integrated, verified: false.
• Spot-checked against Apple's launch specs: 14" M3 Pro 18 GB/512 GB $1,999; 16" M1 Pro 16 GB/512 GB $2,499.

A second commit adds 6 Intel models whose tables are regular: MacBook Air 13" 2018/2019/2020 and MacBook Pro 16" 2019 and 13" 2020 (two and four Thunderbolt 3 ports). It also records the dedicated GPU where there is one. 2017 models are skipped because they exist as variant groups. The 2016–2019 MacBook Pro tables use a different memory row label, and pre-2016 tables are irregular, so both are left for later. Related: #267 (M-series SoCs).

Closes #1