Route QA group through the reserved qa= keyword in run_tests

[ChrisRackauckas-Claude]

Problem

The QA matrix entry of tests CI on main fails for both julia 1 and julia lts:

ERROR: LoadError: ArgumentError: run_tests: GROUP="QA" was requested but no `qa` body was provided
   @ SciMLTesting ~/.julia/packages/SciMLTesting/.../src/SciMLTesting.jl:959
   @ ~/_work/BaseModelica.jl/BaseModelica.jl/test/runtests.jl:20

This was introduced by #134, which rewrote test/runtests.jl to the SciMLTesting v1.2 explicit-args run_tests form but registered the QA group via groups = Dict("QA" => qa_group).

In the explicit-args dispatcher, "QA" (like "Core"/"All") is a reserved group name: when GROUP=QA is requested it is resolved against the qa= keyword and is not looked up in the groups Dict. With qa left unset (default nothing), the reserved-name branch throws.

Fix

Pass the existing qa_group thunk through the reserved qa= keyword instead of groups:

-    groups = Dict("QA" => qa_group),
+    qa = qa_group,

GROUP=QA and the "Quality" umbrella alias both resolve to qa_group; GROUP=Core and the curated GROUP=All (all = ["Core"]) are unchanged. The prerelease no-op guard inside qa_group is preserved.

Local verification

Against the registered SciMLTesting v1.2.0 (the build CI resolved) on Julia 1.10, with a stub thunk to exercise the dispatcher:

=== BROKEN form (current main), GROUP=QA ===
THREW: ArgumentError: run_tests: GROUP="QA" was requested but no `qa` body was provided

=== FIXED form ===
GROUP=Core     => ["CORE"]
GROUP=QA       => ["QA"]
GROUP=Quality  => ["QA"]
GROUP=All      => ["CORE"]

The broken form reproduces the CI error verbatim; the fixed form routes every GROUP correctly. Runic (v1.7) reports test/runtests.jl is already formatted.

Please ignore until reviewed by @ChrisRackauckas.

🤖 Generated with Claude Code

---

Follow-up: fix the genuine JET report exposed once the QA group runs (Julia 1.12)

With the QA routing fixed above, the QA matrix entry on the julia 1 channel
(now 1.12) actually runs test/qa/test_jet.jl, which exposed a single genuine
report_package MethodError in BaseModelica's own source at
src/evaluator.jl (eval_AST(::BaseModelicaWhenEquation)):

no matching method found `kwcall(::@NamedTuple{affect_neg::Nothing,
  discrete_parameters::Vector{Any}}, ::Type{SymbolicContinuousCallback},
  ::Vector{Vector{Equation}}, ::Vector{Equation})` (1/2 union split)

Root cause: to_zero_crossing/eval_when_rhs return a Union whose vector arm
makes crossing ~ 0 inferred as Union{Equation, Vector{Equation}}, so the
array literal [crossing ~ 0] is Union{Vector{Equation}, Vector{Vector{Equation}}}.
The Vector{Vector{Equation}} arm has no matching SymbolicContinuousCallback
method — a real method error on that inferred path. lts/1.10 didn't exercise
that arm, so it only surfaced on 1.12.

Fix: annotate both SymbolicContinuousCallback zero-crossing literals as
Equation[crossing ~ 0] so they are unambiguously Vector{Equation}. A
when-condition is always scalar, so this is behavior-preserving for valid input
and removes the spurious method path.

Local verification on Julia 1.12.6 against the registered test/qa env: JET
report_package over all 364 top-level definitions now reports 0 errors
("No errors detected"), so test/qa/test_jet.jl:12 passes. Runic v1.7 reports
src/evaluator.jl already formatted.

Please ignore until reviewed by @ChrisRackauckas.