Bun parity: implement Node cluster shared-handle listen semantics on Linux

Tracks native Linux cluster semantics from #66 after deterministic corpus metadata is cleaned up.\n\nThe logical harness currently synthesizes success and EADDRINUSE events without workers or sockets. Native reusePort behavior is not equivalent to Node primary-distributed shared handles.\n\nAcceptance criteria:\n- make cluster exclusive:false listeners share a primary-owned handle across workers\n- keep exclusive:true as child-local binding\n- report EADDRINUSE for the second exclusive bind with Node-compatible ordering\n- add a nonempty logical cluster event-order regression\n- add a real Linux multi-process socket test\n- preserve Bun.serve reusePort behavior independently\n\nParent tracker: #66

Adapters/cluster/assert and abort propagation checkpoint (2026-10-10): source 9a78bf246 and verified evidence. Home owns 143 registry modules plus the test adapter, adding eighteen connected modules, NodeFetch/Undici factories and native event registration/dispatch/removal. 25/28 selected implementation/header files match the pin; three native sources implement propagation resistance with unchanged linked layouts. The original abort-listener process initially failed its mustCall check despite seven reported passing cases. Native registration-level resistance now clears that failure; once/removal/destruction cleanup and ordinary DOM propagation remain verified. 56 unchanged originals: 279 registered passes plus 31 process checks, zero failures, skips or TODOs. Eight native groups, final Home ABI 111 tests / 1,637 assertions and Debug 34/34 pass. Build peak 5,641 MB under 8,192 MB; ABI 403 MB, original runs 242/175 MB under 3,840 MB. 638 committed archives verify and 56 reports restore. Earlier process/manifest/compile failures and interrupted gates remain without final credit. This batch edits no fixtures/assertions/deadlines. Cluster SCHED_NONE remains #431; imported Node internal-Undici/HTTP2 remains #867. Remaining registry/native dependencies, complete suite and Release/ASAN/all-platform verification remain unfinished.