Test graph edge order without symbolic repr

[ChrisRackauckas-Claude]

Please ignore this PR until it has been reviewed by @ChrisRackauckas.

Summary

• Assert the exact reaction-to-complex-edge permutation returned by ComplexGraphWrap.
• Remove the brittle comparison against repr strings whose commutative factor order changes across Symbolics versions.
• Keep the adjacent edgelist[rxorder] == Graphs.edges(img) assertion unchanged.

Root cause

Commit a815230d89c2b21c7f9322545043f922654fc6f1 changed the label-order assertion from @test to @test_broken. Under the downgrade workflow's outer-Catalyst load order, the equality already passes, so @test_broken raises an Unexpected Pass. Under the current standalone Extensions environment, Symbolics prints the same commutative product as B(t)*k5 rather than k5*B(t), so a literal string assertion cannot be valid in both supported environments.

edgelabels is deterministically derived from reactions(rn), while rxorder is the mapping under test. Asserting rxorder == [1, 4, 6, 2, 5, 3] preserves the complete ordering invariant without coupling the test to symbolic pretty-printing.

Local validation

• Julia 1.10.11: GROUP=Extensions julia +1.10 --project=. -e 'using Pkg; Pkg.test()' — passed, including Graph visualization 25/25 and the full Extensions group.
• Exact outer-Catalyst/inner-extension downgrade reproducer with DiffEqBase 7.2.0 and JumpProcesses 9.26.0 — Graph visualization 25/25.
• Runic 1.7.0 check of the changed assertion — passed.
• A full-tree Runic check was also run; current master has broad pre-existing formatting drift, so no unrelated formatter rewrite is included here.

[ChrisRackauckas-Claude]

Investigation scratchpad

• Clean base: ae55024af9289d201b353d27859b29909a5e3bde.
• The initial targeted GROUP=Extensions control did not reproduce the Unexpected Pass because it activates the extension environment before loading Catalyst.
• Matching GROUP=All load order—load Catalyst from the outer downgrade environment, then activate test/extensions—reproduced the Unexpected Pass deterministically. The mapping was rxorder = [1, 4, 6, 2, 5, 3].
• Boundary checks against the unchanged graph test:
  • ae55024: 24 passes + 1 Unexpected Pass.
  • 9d3448a6e614f2ddcd7b5c4866a7347266b2b6fd: 25/25 passes.
• A formal git bisect run across the 13-commit range identified a815230d89c2b21c7f9322545043f922654fc6f1 as first bad. Its relevant change was only @test edgelabels[rxorder] == labels → @test_broken ....
• Current standalone Extensions dependencies expose why restoring the literal string assertion is insufficient: the equivalent symbolic product prints as B(t)*k5, while the downgrade graph prints k5*B(t).
• The replacement assertion checks the exact permutation directly. This is equivalent to the intended ordering invariant because edgelabels was deterministically constructed from reactions(rn); the independent adjacent assertion edgelist[rxorder] == Graphs.edges(img) remains unchanged.

Final local validation on commit fb848eaf:

• GROUP=Extensions julia +1.10 --project=. -e 'using Pkg; Pkg.test()': passed. Graph visualization 25/25; complete Extensions group passed.
• Exact outer-Catalyst/inner-extension downgrade reproducer, with Catalyst loaded from this branch, DiffEqBase 7.2.0, and JumpProcesses 9.26.0: 25/25 passed.
• Runic 1.7.0 check of the changed assertion: passed. Full-tree Runic was also executed and reports unrelated pre-existing formatting drift on master; this focused PR does not include that rewrite.

[ChrisRackauckas-Claude]

CI watch update — final terminal state

• All directly relevant Extensions checks are green:
  • Extensions Tests (lts) — passed in 26m50s
  • Extensions Tests (1) — passed in 44m27s
  • Extensions Tests (pre) — passed in 41m48s
• The long build job also passed in 1h42m23s.
• Tests (1, QA) did not report a Catalyst test failure. During JET analysis, after reaching 1044/1455 top-level definitions, the hosted runner emitted:
  • The runner has received a shutdown signal.
  • Julia then exited with signal 15: Terminated.
    The LTS and prerelease QA lanes both passed.
• I attempted to re-run only the affected QA job (87818281731) so the known Modeling failures would not be restarted:
  1. GitHub CLI/REST: HTTP 403, Must have admin rights to Repository.
  2. Connected GitHub app: HTTP 403, Resource not accessible by integration.
• Maintainer action is therefore required: use Re-run job on the Julia 1 QA job.
• The only other red checks are the three Modeling lanes, all failing at the same unchanged symbolic_stoichiometry.jl:235 call with UndefKeywordError: parent_sys not assigned. That clean-master regression is handled separately by draft Test symbolic jump affects through public API #1509; it is outside this PR's GraphMakie-only diff.
• Every other test lane passed. The branch is still synchronized with its remote and has zero commits behind current origin/master.

No #1515 code change is indicated by the remaining red checks.