chore: update environment.yml dependencies and clean channels

fix: skip stuck deploy

docs: pre-release version of 'GitVerse vs GitHub' topic

docs: finish Ch 4: theory and exercises

chore: sync myst.yml and toc.yml with new structure

chore(layout): re-engineer directory tree, cluster chapters with data assets, and standardize intro filenames

chore(layout): relocate sandbox and about to appx, and move index.md to draft

docs: complete Ch 4 theory, pending exercises

docs: add 'Guide structure' section

chore: add jupyterlab_execute_time to environment

docs: refine content across chapters 2-3, and sakila, and index

docs: finish Ch 3, create terms index, and add Ch 4

docs: advance Ch 3; solve Ex 3.1 and truncate SQL output via Polars

docs: add intro5-deploy.md section on auto-publishing

docs: add intro4-git.md and update intro section

docs: rewrite environment and expand Get Started section

build: refactor environment.yml for cross-platform support Switch to polars[rtcompat] to fix 'Kernel Died' error on legacy CPUs Remove OS-specific dependencies and pin core versions for reproducibility

chore: update polars/env, resume working on ch 3

refactor: remove helpers/tutorial/ directory

feat: add sakila app, start ch 3, and refine structure

docs(ch02): add front matter, add markdown code cells, and hide executable cells

docs: finished chapter 2

refactor: mv tutorials files to tutorial/

build: create .env and db_connect.py

chore: install jupyter notebook 7.4.5 and update environment.yml

docs: add sandbox.ipynb for testing myst features

build(env): create environment.yml for project

docs(intro): use kbd roles for keyboard shortcuts