0.3.1

Documentation and diagnostics release for the PHPUnit 8/9 maintenance series, mirroring 1.1.1. Supported versions
are unchanged (PHPUnit ~8.0 / ~9.0 on PHP >= 7.2), and no test needs changing.

Upgrade note. A run whose phpunit.xml does not register CounitExtension now prints one notice line on
STDERR. Exit codes are untouched, and COUNIT_SILENCE_TEARDOWN_NOTICE=1 silences it alongside counit's other
notices.

Added

• A missing CounitExtension registration is announced instead of quietly invalidating the run. The extension
  is what waits for every coroutine to drain before PHPUnit takes its summary; without it nothing does, so the run
  reports a time that can understate the truth by orders of magnitude and assertion totals that are neither correct
  nor consistent between a full run and the same tests run in isolation — while exiting 0 and looking entirely
  healthy. The run's first coroutine now writes a notice to STDERR naming the omission, what it costs, and the
  <extensions><extension class="Deminy\Counit\CounitExtension"/></extensions> element that fixes it. PHPUnit 8/9
  have no extension bootstrap() method, so registration is observed through the BeforeFirstTestHook this class
  already implements — PHPUnit calls it for every registered extension before the first test — which no
  configuration shape can register the extension without firing; a run without Swoole, or a suite that creates no
  coroutine, stays quiet. Verified on PHPUnit 9.6.36 and on 8.0.6, the matrix floor. (d2742ec)

Changes

• CounitExtension is documented as required, not optional. README.md listed registering it under "Optional
  steps" and docs/compatibility.md never mentioned it at all, though nearly every
  guarantee in that matrix depends on it. Both now say so, and both record
  that the registration element differs by release line — <extension class> on PHPUnit 8/9 (counit ^0.3) versus
  <bootstrap class> on PHPUnit 10+ (counit ^1.1), since the class implements different interfaces on each — so
  a snippet copied across lines fails silently. The class docblock carries the snippet too, for anyone arriving
  from a stack trace rather than the README. (9e01e12)
• The install instructions point at the current releases. The documented constraint ~0.2.0 reads as

  = 0.2.0 < 0.3.0, so anyone following the README pinned themselves to the previous line. It is now ^0.3, which
  stops at the next 0.x minor — on a zero-major, where a breaking change may land, and the opt-in boundary 0.3.0's
  behavioral changes want; the table's 1.x rows become ^1.1 in step. The branch note is corrected as well: it
  promised bug fixes and security updates only, which 0.3.0 was not — this line now takes the compatibility work
  the 1.x line develops, back-ported where it applies. (8243c5c)

Full changelog: 0.3.0...0.3.1