From d0de8e8a1ab4a6a24e216e3ff27dfd2362630052 Mon Sep 17 00:00:00 2001
From: Ed_ <edwardgz@gmail.com>
Date: Sat, 20 Jun 2026 00:18:29 -0400
Subject: [PATCH] TIER-2 READ conductor/code_styleguides/error_handling.md
 end-to-end before Phase 7: re-read Thread-safe Result accumulation guidance
 (lines 244-251), Drain Plane section (lines 396-470, especially Pattern 4
 telemetry emission), and the Result-recovery pattern (lines 396-460). Phase 7
 covers worker/background sites that run on the io_pool thread; the canonical
 drain is pp.controller._report_worker_error(op_name, result) which acquires
 pp.controller._worker_errors_lock on append. The lock protects against
 concurrent appends from multiple worker threads corrupting the list (per
 app_controller.py:855-856).