fix: attribute save_to_* deprecation to caller

[davidberenstein1957]

What changed

• codecarbon/emissions_tracker.py: the save_to_* DeprecationWarning now computes its stacklevel dynamically (_caller_stacklevel()) instead of hardcoding stacklevel=2, so it is attributed to the code that constructed the tracker.
• codecarbon/cli/monitor.py: dropped save_to_logger=False, which was both the default and the only reason the CLI tripped its own deprecation check.
• codecarbon/cli/main.py: monitor now passes an explicit output_methods= list built from the user's configuration, with OutputMethod.API added or removed according to --api / --no-api; detect now passes output_methods=[].

Why

_resolve_output_methods is called from BaseEmissionsTracker.__init__, so stacklevel=2 pointed at emissions_tracker.py itself. Python's default ignore::DeprecationWarning filter then dropped the warning for every caller that is not a top-level __main__ script — the users the deprecation was written for never saw it.

A fixed stacklevel=3 would not work either: OfflineEmissionsTracker.__init__ adds a frame, and its @suppress(Exception) decorator adds a contextlib frame on top of that. Walking the stack to the first frame outside the package handles all entry points, including @track_emissions.

Because the corrected attribution makes the warning visible, the CLI's own deprecated call sites had to move to output_methods= in the same change, otherwise every codecarbon monitor / codecarbon detect invocation would warn users about a choice the CLI made (and hard-fail under -W error::DeprecationWarning).

⚠️ Behaviour changes this drags along

Migrating the CLI off save_to_api= is not a like-for-like swap, because output_methods= and save_to_* do not compose the same way: when output_methods resolves to a non-empty value (from the constructor or from configuration), _resolve_output_methods derives all five save_to_* flags from it and returns early. So output_methods replaces, where save_to_api=True added. Two consequences, both now handled:

1. --api must stay additive. An earlier revision of this PR passed a hardcoded output_methods=[OutputMethod.CSV, OutputMethod.API]. That replaced the user's configuration outright: someone with save_to_prometheus = true (or output_methods = prometheus) in .codecarbon.config running codecarbon monitor --api would silently lose Prometheus and silently gain an emissions.csv they never asked for. That is not what save_to_api=True did, so it is now built from the configuration instead, via a small _configured_output_methods() helper that mirrors the tracker's own config-only resolution.

As a side effect this also fixes a pre-existing hole: on master, --api was silently ignored whenever output_methods was set in configuration, because the explicit save_to_api=True lost to the early return. It now works.

2. --no-api has to keep working. api defaults to True, so --no-api is the off switch. master passed save_to_api=False unconditionally, which forced the API off regardless of configuration. Passing the flag only when it is set — as an earlier revision of this PR did — would have made --no-api a no-op for anyone with save_to_api = true in their config file: plain codecarbon monitor would have started pushing to the API and there would have been no way to turn it off from the command line. monitor therefore always passes output_methods=, with API removed when --no-api.

The same applies to save_to_logger=False, dropped from codecarbon/cli/monitor.py: configuration now decides. Since monitor passes an explicit output_methods= list on the online path, that list is authoritative there; run_and_monitor under --offline no longer forces the logger off, which is the intended "configuration wins" direction.

Given that --api / --no-api now both map cleanly onto add/remove, a tri-state Optional[bool] ("unset = whatever the config says") is not proposed here: with api=True as the default, an unset third state would be unreachable from the command line without also flipping the default, which is a separate, user-visible CLI change. Happy to do it as a follow-up if you would rather codecarbon monitor default to the configuration.

How it was verified

• New tests/test_emissions_tracker.py::test_deprecation_warning_points_at_caller asserts the recorded warning's filename is the test module for both EmissionsTracker and OfflineEmissionsTracker. It fails on master and passes here.
• New tests/cli/test_monitor.py::test_run_and_monitor_does_not_pass_deprecated_flags asserts the CLI passes no save_to_* kwarg to the tracker. Also fails on master.
• New parametrised tests/cli/test_cli_main.py::test_monitor_api_flag_adds_to_configured_output_methods pins the additive contract for a configured output_methods = prometheus, for save_to_file=false + save_to_logger=true, and for the already-contains-API no-duplicate case.
• The two --no-api tests now assert OutputMethod.API not in output_methods rather than that no output_methods kwarg was passed.
• Reverting the _configured_output_methods() call back to the hardcoded [CSV, API] makes four of these tests fail, so they are real guards.
• uv run pytest tests/ -q --ignore=tests/test_viz_data.py and uv run pre-commit run --all-files both pass.

Closes #1323

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 96.77419% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.46%. Comparing base (065d0e6) to head (91f3285).

Files with missing lines	Patch %	Lines
codecarbon/emissions_tracker.py	92.85%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1346      +/-   ##
==========================================
+ Coverage   91.39%   91.46%   +0.06%     
==========================================
  Files          49       49              
  Lines        5056     5085      +29     
==========================================
+ Hits         4621     4651      +30     
+ Misses        435      434       -1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.