fix: close redundant PRs + friendly error on all design commands (v0.15.8.1) (#817)

* fix: friendly OpenAI org error on all design commands

Previously only generate.ts showed a user-friendly message when the
OpenAI org wasn't verified. Now evolve, iterate, variants, and check
all detect the 403 + "organization must be verified" pattern and show
a clear message with the correct verification URL.

* test: regression test for >128KB Codex session_meta

Documents the current 128KB buffer limitation. When Codex embeds
session_meta beyond 128KB, this test will fail, signaling the need
for a streaming parse or larger buffer.

* chore: bump version and changelog (v0.15.8.1)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

VERSION

@@ -1 +1 @@
-0.15.8.0
+0.15.8.1