Issue Description

The built-in Sentry::Rails::ErrorSubscriber receives the handled: parameter from Rails.error.report() but never passes it through to the Sentry mechanism. All errors end up as handled: false regardless of how they were reported.

The root cause is in Integrable#capture_exception (line 19):

  hint[:mechanism] ||= Sentry::Mechanism.new(type: integration_name, handled: false)

Since the ErrorSubscriber never sets hint[:mechanism], the ||= always kicks in with handled: false.

Suggested Fix

In Sentry::Rails::ErrorSubscriber#report, set the mechanism before calling capture_exception:

hint[:mechanism] = Sentry::Mechanism.new(type: Sentry::Rails.integration_name, handled: handled)

Reproduction Steps

Report a handled warning

Rails.error.report(
    StandardError.new("handled warning"),
    handled: true,
    severity: :warning
  )

Check the resulting event in Sentry, the handled tag will show no.

Expected Behavior

The event should have handled: yes since handled: true was passed to Rails.error.report()

Actual Behavior

The event always has handled: no because Integrable#capture_exception defaults the mechanism to handled: false and the subscriber never overrides it.

Ruby Version

3.2.6

SDK Version

6.3.1

Integration and Its Version

sentry-rails 6.3.1

Sentry Config

Sentry.init do |config|
  config.dsn = "..."
  config.rails.register_error_subscriber = true # default
end