Add declarative DSL for authoring numba-compiled neuronumba models

[neich]

Summary

Introduces a new DSL layer under src/neuronumba/simulator/models/dsl/ that lets users declare models as plain Python dataclasses and generates equivalent numba-compiled dfun and coupling functions at runtime. All five existing models (Hopf, Deco2014, Montbrio, Naskar2021, Zerlaut) are ported to DSL specs in examples/dsl_models/ and validated against their hand-written counterparts by a full test suite covering spec validation, DAG-based dependent parameters, helper functions, matrix params, delayed coupling, and end-to-end trajectory equivalence.

Commits

• 47f6477 feat(models): update exports to include dsl submodule
• 6991462 docs(dsl_models): add readme for dsl model specs and usage
• c6deab6 feat(dsl_models): add package init with dsl model exports
• c539bf2 feat(dsl_models): add deco2014 dsl spec with dfun and coupling
• 666e369 feat(dsl_models): add hopf dsl spec with diffusive coupling
• e7bf02c feat(dsl_models): add montbrio dsl spec with six state variables
• 6798263 feat(dsl_models): add naskar2021 dsl spec with inhibitory plasticity
• 2a7f3a6 docs(dsl): add readme for dsl declarative model system
• 420dfe4 feat(dsl): add public api init for declarative model dsl
• 413e917 feat(dsl): add builder module to generate model from spec
• e2d31cc feat(dsl): add dependent parameter dag analysis and topo sort
• e757c63 feat(dsl): add on-disk module materialization for numba cache
• a7bbdbc feat(dsl): add ast rewriter to transform equations to numba form
• e83ecd1 feat(dsl): add spec dataclasses for model declaration
• ca7dc90 test(tests): add shared fixtures for dsl test suite
• cda71e9 test(tests): add spec and equation validation unit tests
• 4b4ac1a test(tests): add dependent parameter dag and evaluation tests
• ae65e4a test(tests): add dfun and coupling equivalence tests for dsl models
• 0bf4043 test(tests): add ux polish and cache dir configuration tests
• 986c43c test(tests): add end-to-end simulator trajectory equivalence tests
• e3ba89d test(tests): add subclass recursion regression tests for dsl models
• 81eaa82 feat(dsl_models): add paired simulation comparison script
• 84b5aa6 feat(simulator): rename HistoryDense to HistoryDelays and fix buffer init
• 86c8101 docs(dsl): update readme with parameter and coupling clarifications
• 2234dc6 feat(dsl): update dfun builder to use closure-based param capture
• a9ef80b feat(dsl): update dependents to allow model context names in formulas
• 6e9b7c6 feat(dsl): update rewriter to support helper functions in dfun bodies
• e6dbc71 feat(dsl): update spec to support matrix params and delayed coupling
• c2f312f feat(simulator): update configure to wire HistoryDelays with tract delays
• 5b286e0 test(tests): update dependents tests to verify dfun closure capture
• a5ba031 test(tests): add delayed coupling spec and equivalence tests
• 35cc534 test(tests): add helper function callable from dfun tests
• 0c243d9 test(tests): add numerical jacobian shape and correctness tests
• 8d691a6 test(tests): add matrix-shaped dependent parameter closure tests
• 92b8cca test(tests): add on_configure escape hatch and fic use case tests
• a9c6a71 docs(dsl_models): update readme with loc counts and builder api docs
• 7f7a450 feat(dsl): update public api to export modelbuilder class
• c29ab68 feat(dsl): add fluent incremental builder for modelspec assembly
• 0a8a471 test(tests): add modelbuilder chaining and imperative style tests
• 04f4c1c docs(dsl_models): update readme with zerlaut port and feature coverage
• 4688a8c feat(dsl_models): update exports to include zerlaut dsl models
• fee5dfa feat(dsl): update rewriter to support tuple-unpacking assignments
• 668667b feat(models): update zerlaut dfun to hoist m_aux out of jit closure
• 55276b0 test(tests): update conftest to add zerlaut spec and class fixtures
• 8041113 test(tests): update equivalence tests to cover zerlaut models
• 54bab4b test(tests): update helpers tests to cover tuple-unpacking cases
• 4fba908 feat(dsl_models): add zerlaut dsl spec with first and second order
• 9da14e3 docs(dsl_models): update readme with per-spec usage guide