config: add per-repo TOML schema and parser

[lykimq]

Summary

• Add [repositories.*] config for per-repo settings (project number, teams, jobs, minimizer URL, etc.)
• Add Repo_config parser + lookup helpers, and load the table at bot startup
• Extend Utils with TOML helpers for nested tables, ints, bools, and string arrays

No behavior change yet: hardcoded repo checks are unchanged. Later PRs will switch actions/webhooks to this config.

Test plan

• dune build
• dune exec tests/test_repo_config.exe (full/minimal/bad github/missing section/find miss)
• Confirm existing bot startup still works with the updated coqbot-config.toml

[Zimmi48]

Looks promising!

[Zimmi48]

Can we make this more explicit, like backporting_github_project_number or even move it to a backporting subsection?

[lykimq]

I have update it in the commit 32632cf

[Zimmi48]

Can we make this into something more generic like a section with a team_name field and a permission field which would be a free text string?

[lykimq]

I have split them into a section teams, this is the commit: 32632cf

[Zimmi48]

This one is a bit special, it's just to @-mention someone to alert them (IIRC). We could provide directly the full @-mention, that would be more flexible.

[lykimq]

I changed it to alert_mention. 32632cf

[Zimmi48]

What is this one?

[lykimq]

The jobs section is for the repo-specific CI behavior (it will be used by the job handling flow, including doc status handling).

in the job.ml, bench.ml, documentation.ml

• bench_job: name of the CI job treated as the bench job. That job uses the bench-specific path (bench status / bench summary/comment)

 match (github_repo_full_name, job_info.build_name) with
      | "rocq-prover/rocq", "bench" -> ...

• use_rocq_job_status: enables Rocq-specific failures/status formatting. true use Rocq custom failure handling, and false use the generic failure/status messages.

 match job_info.build_status with
        | "failed" ->
            let failure_reason = Option.value_exn job_info.failure_reason in
            let summary_builder, allow_failure_handler = 
              if String.equal github_repo_full_name "rocq-prover/rocq" then
...

it can be config as:

   | "failed" ->
        let use_rocq =
          Option.value_map repo_cfg ~default:false
            ~f:(fun cfg -> cfg.jobs.use_rocq_job_status)
        in
        let summary_builder, allow_failure_handler =
          if use_rocq then
            ( Job_status_rocq.rocq_summary_builder
            , Job_status_rocq.handle_rocq_allow_failure )
          else
            (generic_summary_builder, generic_allow_failure_handler)
        in

• doc_artifact_jobs: list of doc jobs that should publish documentation (in the documentation.ml)

[Zimmi48]

All your PRs are good to merge for me. I let you do it in the order that you prefer, because there might be some merge conflicts.