docs: polish first three parts for Springer submission

[cwang0810]

Summary

• Polish Part 1 through Part 3 toward Springer-style chapter delivery, including chapter abstracts, keywords, learning objectives, and neutral technical prose.
• Expand Part 2 and Part 3 guide pages with positioning, prerequisites, learning objectives, chapter logic, and cross-part transitions.
• Revise Part 2 and Part 3 chapters to clarify anonymized composite cases, dynamic estimate scopes, code-listing/table conventions, and figure/table production metadata.
• Update publishing/12_figures_tables_register.md with Part 2 and Part 3 figure/table source, alt text, first-reference, and high-resolution source notes.

Validation

• python scripts/publish_lint.py --json /tmp/part23_publish_lint.json
  • Full-book command still exits non-zero due to existing issues outside Parts 1-3, especially Part 10 broken local image paths, Part 12 draft/stub chapters, and later-part missing abstracts/keywords/references.
  • Filtered Part 2 and Part 3 results show 10 scanned Part 2/3 files with empty issues arrays.
• python scripts/xref_scan.py --json /tmp/part23_xref.json
  • Full-book command still exits non-zero due to existing issues outside Parts 1-3, including docs/zh/abbreviations.md part-style warnings and Part 10/12 cross-reference issues.
  • Filtered Part 2 and Part 3 results show 0 issue objects.
• python scripts/check_tone.py --root docs/zh/part2 --warn-only
• python scripts/check_tone.py --root docs/zh/part3 --warn-only
  • Both tone checks passed with no tone violations.
• rg check for the listed colloquial/overdramatic phrases across Parts 1-3 returned no matches.
• python scripts/publish_lint.py --md /tmp/publish_lint.md
  • Full-book report generated, still non-zero from known full-book issues outside this PR scope.
• python -m mkdocs build --clean
  • Still blocked by the existing docs/superpowers / mkdocs_static_i18n default-language duplicate-file conflict.

[cwang0810]

Closed because this PR was opened against the wrong repository. The corrected PR will be submitted to datascale-ai/data_engineering_book.