v1.0.0-rc.2

Added

• OTelAPI.setErrorHandler — a user-configurable global error handler
  (api#94). Internal misuse reports route through it instead of throwing;
  the default handler logs via OTelLog and never throws. A user-installed
  handler that throws propagates deliberately (strict mode), per
  error-handling.md. The handler is factory-held state: OTelFactory
  carries the installed handler and an overridable defaultErrorHandler
  for SDK factories, and a handler installed before any factory exists
  is buffered and adopted at factory installation. Context.runIsolate
  re-installs the parent's handler inside the child isolate (handlers
  are copied; capture a SendPort to aggregate reports across isolates
  — an unsendable handler degrades to the child default and is
  reported).

Fixed (spec compliance)

• Span.end() no longer promotes status from Unset to Ok (api#60).
  Unset stays Unset; analysis tools can no longer be misled by
  fabricated Ok statuses. The deprecated spanStatus parameter still
  flows through the setStatus rules when passed.
• CompositePropagator.extract walks propagators in the order they were
  specified (api#76), matching inject and every other OpenTelemetry SDK
  (was reversed, so the last-registered propagator no longer wins extract).
• Context.withSpanContext returns a derived Context instead of throwing
  ArgumentError when the context already holds a span from a different
  trace (api#77) — a routine situation during extraction.

Added

• Semantic conventions regenerated from registry v1.44.0 (previously
  v1.43.0-21-g436fa257). Additive only, per the VERSIONING.md policy: 47
  new identifiers, no renames and no removals.

  The substantial addition is the complete browser.web_vital.* set —
  name, value, delta, id, rating and navigation_type — together
  with their value enums: cls, lcp, fcp, inp, ttfb and the
  obsoleted fid; good / needs-improvement / poor; and the six
  navigation types (navigate, reload, back-forward,
  back-forward-cache, prerender, restore). Web-vitals instrumentation
  now has registry names to emit against instead of inventing its own.

  Also new: browser.platform, hw.errors and hw.status,
  k8s.node.filesystem.inode.count / .free, and the scaleway_cloud
  and scaleway_cloud_compute members.

• lib/src/api/semantics/candidates/ — a home for attribute keys that are
  not yet in the registry, staged for upstream contribution, exported from
  the package barrel and marked @experimental.

  This revisits the rc.1 position that "the API package now contains only
  registry conventions". That rule was right about the problem — a private
  dialect masquerading as OpenTelemetry — but it left no path for the
  conventions we want to propose, which the semantic-conventions CONTRIBUTING
  guide asks be "prototyped in the corresponding instrumentation(s)" first.
  Candidates are kept in a separate directory, under a separate stability
  promise, so a consumer can always tell a published convention from a
  proposal.

  Candidates are unstable in identity but deprecation-cycled: a renamed,
  reshaped or rejected candidate is @Deprecated, pointing at its
  replacement, for a release before it is removed — the same cycle the
  vendor/RUM enums completed. When one is accepted upstream it reappears in
  generated semconv/ output and the candidate is deprecated in its favor.

  Staged: app.start.type (cold/warm/hot), app.launch.id,
  app.screen.previous_id, app.screen.previous_name,
  app.gesture.direction, app.gesture.delta.x, app.gesture.delta.y,
  device.battery.level, device.battery.state, device.battery.save_mode,
  device.emulator, and browser.languages.

• doc/SEMCONV_CANDIDATES.md — the disposition of all 116 identifiers
  removed in rc.1. Most should return as registry conventions rather than
  candidates: the registry has since gained app.crash, app.jank,
  app.screen.click, app.widget.click, device.app.lifecycle,
  session.start/session.end and browser.web_vital.*, which cover the
  bulk of the removed RUM surface. The document maps each removal to its
  registry replacement, to a candidate, or to a recorded reason for dropping
  it.