Sampling binary profiles do not record the profiling mode

[pablogsal]

Bug report

Bug description:

The sampling binary header does not record --mode. Replay and differential flamegraphs therefore cannot describe or validate how the baseline was collected.

python -m profiling.sampling run --mode cpu --binary -o baseline.bin demo.py
python -m profiling.sampling replay --flamegraph -o replay.html baseline.bin
python -m profiling.sampling run --mode wall --diff-flamegraph baseline.bin -o diff.html demo.py

The replay has no CPU-mode metadata, and the differential run silently compares a CPU baseline with a wall-time profile. These measurements are not comparable.

CPython versions tested on:

3.16

Operating systems tested on:

Linux

Linked PRs

• gh-154090: Store profiling mode in binary files #154105