Upgrade to Effect rc.112, TypeScript 7, and Bun 1.4.1

[FNDEVVE]

Summary

• Pin Effect and platform packages to 4.0.0-rc.112; update schema errors, JSON codecs, and WebSocket send types for the current APIs.
• Replace the old native-preview / TypeScript 5 compiler split with TypeScript 7.0.2 and @effect/tsgo 0.39.1, patched through prepare; require TypeScript ^7.
• Raise minimum Bun to 1.4.1, align CI/release workflows, and update Bun types, Vitest, and formatting/lint tooling.
• Remove obsolete beta.83 skipLibCheck guidance and the generated-consumer workaround.
• Preserve Node support, the public recorder API, and cassette v1. Add a separate minor changeset for the raised compatibility requirements; leave the existing cassette-helper changeset untouched.

Verification

• bun install --frozen-lockfile passed.
• bun run check passed: formatting, lint, static imports, library/test TypeScript checks, 47 recorder tests, 3 recorded examples, and packed-package verification (Node/Bun exports and a clean TypeScript 7 consumer without skipLibCheck).
• A throwaway local HTTP/WebSocket smoke recorded real traffic, stopped the server, then successfully replayed offline. WebSocket replay opened zero live connections. Exhausted, unmatched, and unused exchanges failed, and test secrets were absent from the cassette. The smoke script and temporary recordings were removed.

No cassette recordings or publishing policy changes are included.