Pedagogy: move 00_introduction/40_how_to_draw_a_circle → 06_python_advanced/80_circle_case_study

[kwlee2025cpp]

Goal

00_introduction/40_how_to_draw_a_circle.ipynb is a case study using sympy + numpy + matplotlib to express the same circle three ways (closed, implicit, parametric). With the 00_introduction restructure (motivation only), case studies move to 06_python_advanced. The circle case study is a natural capstone after numpy + matplotlib basics.

Scope

Move 00_introduction/40_how_to_draw_a_circle.ipynb → 06_python_advanced/80_circle_case_study.ipynb. Mechanical move (rename + path adjustment + Colab badge URL update). No content rewrite in this issue.

Suggested ordering within 06_python_advanced/:

• 60_numpy_basics
• 70_matplotlib_basics
• 80_circle_case_study ← uses 60 + 70 + sympy
• 90_pandas

Dependency

• Companion content-completion issue must land FIRST (hint + solution + exercises). Then this move is purely mechanical.

Acceptance

• File moved.
• Colab badge URL updated to new path.
• Internal links / README references updated if any.
• Notebook still runs from new location.