Add error serialisation, source maps, transports, tracing and level control

[developerEhsan]

Errors were the headline bug: log.error(err) printed {} because every interesting field on an Error is non-enumerable or on the prototype, and that is the single most common call a logger receives. serializeError() now covers cause chains, AggregateError, own extras (code, statusCode, Next's digest), non-Error throws, throwing getters and cycles, and dispatch() normalises the four call shapes people actually write — including hoisting data.error and errors nested anywhere inside data. Stacks are stored as frame arrays, not strings, so the formatter can own the line prefix (a relayed frame is attacker-controlled text) and so frames can be source-mapped individually.

Source-map resolution turns minified relayed browser stacks and the Turbopack chunk path in caller back into real filenames. VLQ decoding is hand-rolled rather than pulling in a WASM trace-mapping library for a best-effort dev-time feature. Filesystem access is deliberately bundler-invisible: process.getBuiltinModule where available, otherwise a dynamic import whose specifier is assembled with a join, because esbuild constant-folds string concatenation back into a resolvable literal and Next's Edge scanner then flags it in every consumer chunk.

Transports gain batching, jittered retry, bounded buffers with counted drops and per-sink isolation, plus file/HTTP/OTLP/Pino/Winston adapters and Datadog, Axiom and Better Stack presets. Throwing from write() means "retry me", so a permanent 4xx returns and reports instead of hammering a vendor forever with a payload it will never accept. The old (entry) => void form still runs inline, unchanged.

Also: uncaught browser errors and unhandled rejections reach the terminal with no call site, additively and without preventDefault; onRequestError and process handlers for instrumentation.ts; time/timer/withLogging; W3C and OpenTelemetry trace correlation; LOG_LEVEL per-namespace rules with last-match-wins precedence; a Redis-backed relay cap that fails open; and optional Standard Schema validation of data that never suppresses a log line.

Two new public entry points (./transports, ./security/rate-limit-redis) plus ./instrumentation, all wired through tsup and the exports map. check-edge-safety now rejects resolvable node: specifiers.

303 tests, typecheck and both build gates pass.