feat: enhance OpenAI response rendering to include reasoning and improve tool call detection from thinking channel, and refactor testing scripts for unified unit test execution.

tests/scripts/run-unit-go.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/../.." && pwd)"
+cd "$ROOT_DIR"
+
+go test ./... "$@"