Python Importtime Optimization

Diagnose and fix slow Python package import times. Procedure distilled from the llamabot case (litellm = 4.1s of a 4.7s import llamabot, 2026-08-16) and the earlier uvicorn fix (PR #388).

Step 1: Profile with -X importtime

python -X importtime -c "import pkg" 2> profile.txt
sort -t'|' -k2 -rn profile.txt | head -30   # by cumulative time

• The cumulative column identifies the hogs; one heavy dependency (litellm: 4.1s) typically dominates the package total (4.7s).
• Interpreter startup + small deps account for the remainder (~0.6s) — don't chase those until the dominant cost is gone.

Step 2: Know the two eager-import sites