Move GlobalDiffEq.jl into the monorepo as lib/GlobalDiffEq (repo transfer)

[ChrisRackauckas-Claude]

Important

Ignore this PR until it has been reviewed by @ChrisRackauckas.

Summary

Repo transfer only: moves GlobalDiffEq.jl into the monorepo as the sublibrary lib/GlobalDiffEq, keeping its name, UUID, and registration lineage (like DelayDiffEq/StochasticDiffEq). No new methods — the package content is GlobalDiffEq.jl master (GlobalRichardson), adapted to monorepo conventions:

• [sources] path deps on DiffEqBase and OrdinaryDiffEqTsit5; the dependency on the OrdinaryDiffEq umbrella is replaced by OrdinaryDiffEqTsit5 (only used by the precompile workload and tests), so the sublibrary does not depend on the whole umbrella.
• Test groups Core (lts/1/pre) + QA (lts/1) via test/test_groups.toml, picked up by the standard sublibrary CI; the group env var is ODEDIFFEQ_TEST_GROUP.
• Docs: new "Global Error Control" section (docs/src/globalerrorcontrol/GlobalDiffEq.md); GlobalDiffEq added to docs/Project.toml (path source) and docs/make.jl modules. The QA group's rendered-API-docs check points at the monorepo docs/src with reexported DiffEqBase names excluded (they are documented at their owners), so "public and documented" stays enforced.
• Version 1.2.1 (no API change).

This is the base of a stacked series that implements the methods from the GlobalDiffEq.jl issue tracker, one feature per PR:

1. this PR — repo transfer
2. GlobalDiffEq: add adjoint-based global error control as a SciMLSensitivity extension #3953 — adjoint-based global error control (Add adjoint-based global error control GlobalDiffEq.jl#56, as a package extension)
3. GlobalDiffEq: add GLEE23/GLEE24/GLEE35 global-error-estimating solvers #3954 — GLEE solvers (Constantinescu 2016; Specialized RK triples for global error control GlobalDiffEq.jl#6, Global error estimation in time stepping GlobalDiffEq.jl#22)
4. GlobalDiffEq: add the Makazaga-Murua MM5GEE solver #3955 — MM5GEE (Makazaga–Murua 2003; Specialized RK triples for global error control GlobalDiffEq.jl#6)
5. GlobalDiffEq: add GlobalErrorTransport global error estimation and control #3956 — GlobalErrorTransport (Jacobian-based global error estimators GlobalDiffEq.jl#5)
6. GlobalDiffEq: add GlobalDefectCorrection global error estimation and control #3957 — GlobalDefectCorrection (Expansion methods for global error control GlobalDiffEq.jl#3)

Once the series merges, SciML/GlobalDiffEq.jl can be archived pointing here.

Validation (run locally)

• ODEDIFFEQ_TEST_GROUP=Core julia --project=lib/GlobalDiffEq -e 'using Pkg; Pkg.test()': pass — Basic functionality 1/1, Algorithm traits 3/3, BigFloat 2/2
• ODEDIFFEQ_TEST_GROUP=QA julia --project=lib/GlobalDiffEq -e 'using Pkg; Pkg.test()': pass — 22 passed, 1 pre-existing declared broken (no_implicit_imports from the deliberate @reexport, QA: ExplicitImports no_implicit_imports broken (deliberate @reexport using DiffEqBase) GlobalDiffEq.jl#53)
• julia --project=docs -e 'using Pkg; Pkg.instantiate()' resolves with the new path source.
• Runic.jl (v1.5.1) run over the sublibrary and touched docs files.

🤖 Generated with Claude Code

https://claude.ai/code/session_01MfUh8tgp3iBmMv9nkBqoyY