Destroy-notify ABI fixed to GClosureNotify's real 2-arg signature and
wired into every connect method (was leaking every _ClosureBox, and
UB on non-x86_64 with the wrong arg count). Trampolines restore
MainActor isolation via assumeIsolated, with narrowly-scoped
nonisolated(unsafe) shadow copies to satisfy Swift 6's sending
checker. Interface-signal rendering implemented and unit-tested.
Dead code removed (SignalHandlePlan), destroyTrampoline made
non-optional, D7 deferral documented in-code. CoverageStats gained
boundCallbacks/boundSignals counters. Added SignalGenerationTests,
InterfaceSignalGenerationTests, and CallbackGenerationTests (12 new
tests, 187/187 total). Fixed the dead nonDetailedSignal smoke test to
actually mutate a property and assert the closure fired.
Callback-param planner-side binding (D4.3) stays disabled: enabling
it trips a genuine Swift compiler crash on g_qsort_with_data's
GCompareDataFunc parameter. The renderer-side box setup/release logic
is implemented and unit-tested by constructing plans directly,
bypassing the blocked planner path.
Verified: swift test (187/187), compile-gate.sh 1 --fresh (PASS),
smoke-test.sh --fresh (18/18).
Brendan Szymanski
5abb48e889