perf: speed up CLI monitor startup and fix wrapped commands (4/4)

[davidberenstein1957]

Summary

Part 4/4 of the tracker performance stack. Depends on #1251 → #1252 → #1253.

cc @inimaz — final CLI layer of the #1246 split. Merging #1251 → #1252 → #1253 → this PR restores the full change set.

Speeds up codecarbon monitor startup and fixes wrapped-command delegation:

• Lazy-import heavy CLI dependencies (questionary, requests, tracker classes, etc.)
• Add --log-level option to codecarbon monitor (default: error)
• Fix wrapped command parsing: strip nested monitor / -- tokens before exec
• Update CLI reference docs for --log-level default

Benchmarks (measured locally, offline Mac ARM, 2026-06-21)

Full stack cumulative vs master:

Metric	master	Full stack (this PR tip)	Δ vs master
Tracker __init__ p50	190 ms	1.0 ms	~99% faster
Cold lifecycle p50 (init→start→stop)	1,685 ms	433 ms	~74% faster (~4×)
Warm lifecycle best (same process)	1,565 ms	5.9 ms	~265× faster
CLI monitor subprocess p50	850 ms	643 ms	~24% faster

Stack

1. perf: defer tracker initialization and slim import path (1/4) #1251 — lazy initialization & import slimming
2. perf: cache hardware detection and optimize warm-path reuse (2/4) #1252 — hardware detection cache & warm-path reuse
3. perf: defer API run creation until first emission upload (3/4) #1253 — lazy API run creation
4. This PR — CLI monitor startup & UX

CI / quality

• pre-commit run --all-files — passed (autoflake, isort, black, flake8)
• pytest tests/cli/ — 59 passed
• Full suite — 535 passed locally (CODECARBON_ALLOW_MULTIPLE_RUNS=True pytest --ignore=tests/test_viz_data.py -m 'not integ_test' tests/)

Test plan

• Manual: codecarbon monitor --offline --country-iso-code FRA -- sleep 1
• Manual: codecarbon monitor --offline --country-iso-code FRA --log-level debug -- python train.py

Replaces

Split from #1246.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.68%. Comparing base (553e852) to head (04e1b47).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1254      +/-   ##
==========================================
+ Coverage   89.62%   89.68%   +0.06%     
==========================================
  Files          48       48              
  Lines        4761     4771      +10     
==========================================
+ Hits         4267     4279      +12     
+ Misses        494      492       -2     

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[davidberenstein1957]

@inimaz — #1246 has been split into this 4-PR stack for easier review. Benchmarks in the description are measured locally (Mac ARM, 2026-06-21); pre-commit and tests pass on each branch. Please start with #1251.

[davidberenstein1957]

@inimaz — #1251 is merged. This PR has been rebased onto the updated stack. CI and local tests pass — ready for your review.

[inimaz]

Nice thanks @davidberenstein1957 !