fix(hir,runtime,stdlib): bare events specifier resolves to full EventEmitter (#4995)

[proggeramlug]

Summary

Fixes #4995. The bare core specifier events (default import, namespace import, or require('events')) produced an EventEmitter whose instances had an empty prototype — .on/.emit/.setMaxListeners all undefined — while node:events worked. This blocked signal-exit (cli-cursor → restore-cursor), the next ink (#348) wall after #4993.

Root cause — two layers, both real

1. HIR lowering. new EE() over an events default import / namespace import / CJS alias lowered to the empty-object placeholder instead of the real EventEmitter. Separately, emitter method-value reads (typeof emitter.on) were gated on the canonical class name — but var EE = require('events') registers the native instance under class name "EE", so an aliased read fell through to a zero-arg events.on() native call that threw ERR_INVALID_ARG_TYPE.

2. A latent, broader bug. Even node:events dynamic dispatch (const x: any = e; x.on(...)) was fully broken in flip binaries. perry-stdlib's handle-dispatch arms called the in-crate crate::events::* registry, but the well-known flip links perry-ext-events, whose handles that registry never sees — so the probe returned false and every dynamic .on/.emit/.setMaxListeners silently no-op'd or read undefined.

Fix

• HIR (expr_new.rs, expr_member.rs): route events default/namespace/alias new to Expr::New { class_name: "EventEmitter" }; gate emitter method-value reads on the module name, not the canonical class name.
• Runtime (tags.rs, handle.rs, class_registry.rs): new js_set_native_events_construct dispatcher so js_new_function_construct builds a real emitter when new lands on a bound events.EventEmitter export value.
• stdlib (common/dispatch.rs, events/domain.rs): handle-dispatch arms (probe / on / constructors) now call the linker-resolved extern "C" events symbols instead of in-crate crate::events::*, so dynamic dispatch consults the same registry the constructors used — mirroring the sqlite duplicate-symbol contract (drizzle: SQLiteInsertBase methods (_prepare, prepare, execute, returning, etc) return undefined when accessed via Any-typed receiver #643). New external-events-construct feature registers the constructor when the well-known flip strips bundled-events.

Validation

• 6-variant repro matrix (named/default/namespace × bare/node:) + the exact signal-exit require('events') pattern all pass.
• New gap test test_gap_events_import_4995.ts — byte-identical vs node --experimental-strip-types.
• Zero gap-suite regressions: my 31 failures are a strict subset of the baseline's 32 (baseline-only test_gap_node_fs is flaky and unrelated). Runtime tests 1022/1023 (the one failure is the pre-existing macOS date test).

Code-only per the maintainer-folds-metadata-at-merge convention (no version bump / changelog).