Match the OrdinaryDiffEq canonical monorepo style: every sublibrary gets a
README with the standard SciML badge block (Zulip, Global Docs, ColPrac,
SciML Code Style) and the "component of the DataDrivenDiffEq.jl monorepo"
wording, plus a one-line description of the sublibrary's role and a link to
the DataDrivenDiffEq documentation.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Match the OrdinaryDiffEq canonical monorepo style, where the root and every
sublibrary ship a LICENSE.md. Content is preserved verbatim (git mv).

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

TagBot.yml: adopt the OrdinaryDiffEq canonical form -- top-level permissions
block, workflow_dispatch.inputs.lookback default "3", a root
TagBot-DataDrivenDiffEq job, and a TagBot-Subpackages matrix (fail-fast:false)
over the four registered sublibraries (DataDrivenDMD, DataDrivenLux,
DataDrivenSR, DataDrivenSparse), each tagging via subdir: lib/<Name>. All four
are registered in the General registry.

Downstream.yml (IntegrationTest): add the canonical downstream integration
workflow. Develops the root umbrella DataDrivenDiffEq plus every lib/*
sublibrary, then runs the downstream repo's tests; ResolverError is treated as
an intentional breaking change (exit 0). Matrix covers the external General
dependents SymbolicNumericIntegration.jl and ODINN.jl.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

… to 1.15

Every lib/* sublibrary now has a [compat] entry for each [deps] and [extras]
package, removing the implicit-unbounded test/stdlib dependencies:

- DataDrivenDMD: add LinearAlgebra, SafeTestsets, StableRNGs, StatsBase, Test.
- DataDrivenLux: add Distributed, LinearAlgebra, Logging, Random, SafeTestsets,
  StableRNGs, Test.
- DataDrivenSparse: add LinearAlgebra, Printf, Random, SafeTestsets,
  StableRNGs, StatsBase, Test.
- DataDrivenSR: add StableRNGs, StatsBase, Test.

Stdlib bounds track the julia = "1.10" floor ("1.10"); SafeTestsets = "0.1",
StableRNGs = "1", StatsBase = "0.34".

Bump the DataDrivenDiffEq compat floor in each sublibrary from "1.14" to "1.15"
to match the in-repo umbrella version (1.15.0). All four sublibraries resolve
against the in-repo umbrella via their [sources] path entries (verified with
Pkg.resolve on Julia 1.11). No floors lowered; only additions and the
umbrella-matching raise.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Add the missing [compat] entries so every root [deps] and [extras] package is
bounded, matching the canonical fully-bounded monorepo style: LinearAlgebra,
Random, Pkg, Test = "1" (stdlibs, consistent with the existing Statistics = "1")
and SafeTestsets = "0.1". Root environment resolves cleanly with these bounds
(verified with Pkg.resolve on Julia 1.11). Only additions; no floors lowered.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Move every test group's files into test/<Group>/ folders, per the
OrdinaryDiffEq canonical dependency-driven group model, at both the root
package and each lib/* sublibrary.

Root (DataDrivenDiffEq):
- Functional tests (basis, problem, solution, commonsolve, utils) move
  from their scattered subfolders into test/Core/; runtests.jl includes
  them from Core/. Core is the base-env group and the only group in All.
- The nopre group (JET static analysis) already lives in test/nopre/ with
  its own Project.toml (JET) — a dep-adding group excluded from All. Its
  name stays lowercase to match the lowercase nopre input in CI.yml.
- Add test/test_groups.toml declaring Core [lts,1,pre] and nopre [lts,1].

Sublibraries (DataDrivenDMD, DataDrivenLux, DataDrivenSparse, DataDrivenSR):
- Each runs only a functional Core group (no QA tooling, no GPU). Move
  the Core test files into lib/<sublib>/test/Core/ and include from there.
  DataDrivenSR's inline runtests body is extracted to
  Core/symbolic_regression.jl. Core adds no deps beyond the base test set,
  so no per-group Project.toml is introduced.
- Normalize each test_groups.toml Core version matrix from
  [lts,1.11,1,pre] to the canonical [lts,1,pre].

No compat floors lowered, no tests skipped/broken/loosened; every test
that previously ran still runs in exactly one group.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

- Replace TagBot.yml with the canonical thin caller to
  SciML/.github tagbot.yml@v1, plus a tagbot-subpackages matrix over
  the registered lib/* sublibraries (DataDrivenDMD, DataDrivenLux,
  DataDrivenSparse, DataDrivenSR; all confirmed in General).
- Downgrade.yml: drop hand-listed stdlib skip (Pkg,TOML) and the
  julia-version: "1.10" pin (central default is lts; auto-populated skip).
- DowngradeSublibraries.yml: drop hand-listed skip (stdlibs + caller
  package), now auto-populated by the centralized workflow.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>