Fix NameError build failures in ml_systems, data_engineering, and
benchmarking chapters caused by missing imports and variables referenced
before their defining code cells.
- ml_systems: add missing Kparam and Bparam imports from physx.constants
- data_engineering: compute transfer_time_10g_md preview in setup cell,
add md_math import, add deduplication-dividend-calc cell, convert
hardcoded values to physics engine units
- benchmarking: compute BERT roofline preview values in roofline-example-calc
cell before they are referenced in narrative text, convert hardcoded
values to inline Python, condense redundant footnotes
Also includes physics engine integration improvements across all Vol 1
chapters: unit-safe conversions, inline Python for previously hardcoded
values, streamlined footnotes with cross-references, and new content
validation scripts.
All 21 Vol 1 chapters pass PDF build tests.
- Renamed vol2/advanced_intro to vol2/introduction for consistency
- Updated all scripts and configs to use vol1/ instead of core/
- Updated pre-commit config to check all contents/ not just vol1/
- Updated path references in Lua filters, Python scripts, and configs
