IOTOF: add in-pixel efficiency (#15786)

* add pixel efficiency map to iotof digitization

* add path to the available file in a comment

* change binning of the histograms

* clang-format

* revert size of the histograms

Publish the CAD support tutorial as MkDocs sources

This converts the single-page tutorial to Markdown, adds a worked example
on the ITS and updates the README pointer.

- doc/tutorial/index.html is replaced by a MkDocs project: mkdocs.yml, one
  page per section under docs/, and the figures as files in docs/images/.
- The pages use GitHub's own alert and fence syntax, so they render in the
  repository file view without a published site.
- hooks/github_alerts.py turns those alerts into Material admonitions at
  build time, so the site needs only mkdocs-material.
- docs/its-round-trip.md is new: the ITS through o2-tgeo-to-cad and back,
  then placed as a sensitive external detector to produce hits.
- The tutorial pointer in README.md now names the directory.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017gNpas1pZ9DNBhVesoM5QZ

Upgrades: clusterer will prioritize labels with lower trackIndex (#15783

)

Extending PR15782 to upgrade classes which replicated the cluster label building from the ITS:
The HIP may produce a large number of delta electrons (e.g. a magnetic monopole typically produces
a few 10K deltas in the barrel). Since we limit the number of saved MC labels per ITS/MFT cluster
to Clusterer::MaxLabels (=10), in a large cluster receiving contributions from both the HIP and
its delta rays, the HIP label might not be saved if MaxLabels delta electrons contributing to the
same cluster have already been accounted for (the order is quasi-random).

To minimize the chance of such label loss, assuming that the track ID of the HIP is smaller
than those of its delta rays, when there is no free slot left in the label buffer, the new
label (e.g. that of the HIP) will replace the label with the largest track ID already present in the buffer.

Add support for VecGeom v2 (#15737)

Implement HepMC reading randomisation

Do not check for token for local CCDB backends

[ALICE3] IOTOF: update id number to current number of chips (#15759)

Please consider the following formatting changes

GPU CMake: Multiple updates

One more warning to silence