docs(ecosystem): complete hub stack consolidation (CUST-WP-0057)

Publish ecosystem architecture, event mapping, capability bridge, and async-base
decision docs; add cross-repo regression script; update extraction boundary and
bootstrap status; archive WP-0058 touch-ups.

scripts/hub-ecosystem-regression.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Cross-repo regression gate for CUST-WP-0057 hub ecosystem consolidation.
+set -euo pipefail
+
+HUB_CORE="${HUB_CORE_ROOT:-/home/worsch/hub-core}"
+STATE_HUB="${STATE_HUB_ROOT:-/home/worsch/state-hub}"
+CORE_HUB="${CORE_HUB_ROOT:-/home/worsch/core-hub}"
+
+run_pytest() {
+  local repo="$1"
+  local label="$2"
+  echo "==> ${label} (${repo})"
+  cd "${repo}"
+  if command -v uv >/dev/null 2>&1 && [[ -f pyproject.toml ]]; then
+    if [[ "${repo}" == *core-hub* ]]; then
+      uv sync --extra dev >/dev/null
+    fi
+    uv run python -m pytest -q
+  else
+    python3 -m pytest -q
+  fi
+}
+
+echo "Hub ecosystem regression gate"
+echo "hub-core:  ${HUB_CORE}"
+echo "state-hub: ${STATE_HUB}"
+echo "core-hub:  ${CORE_HUB}"
+echo
+
+run_pytest "${HUB_CORE}" "hub-core"
+run_pytest "${STATE_HUB}" "state-hub"
+run_pytest "${CORE_HUB}" "core-hub"
+
+echo
+echo "All hub ecosystem test suites passed."