merge: integrate go-agentx runtime into local_dev candidate

Bring pinative/agentx workspace registry and A-B harness onto current
local_dev; renumber goose agentx registry 00062→00066 to avoid clash
with chat-summary/provenance migrations. Keep CURRENT/MATRIX as ours
for later docs apply; union module-boundaries agentx import tree.
Path literals use workspace constants for arch-check.

docker-compose.dev.yml

@@ -82,7 +82,10 @@ services:
       HTTP_ADDR: ":${HTTP_PORT:-8080}"
       HTTP_PORT: "${HTTP_PORT:-8080}"
       HTTP_HOST: "0.0.0.0"
-      AGENT_BACKEND: ${AGENT_BACKEND:-pi-agent}
+      AGENT_BACKEND: ${AGENT_BACKEND:-pi-native}
+      AGENTX_API_BASE: ${MINIMAX_ENDPOINT_URL:-https://api.minimaxi.com/v1}
+      AGENTX_API_KEY: ${MINIMAX_API_KEY:-}
+      AGENTX_MODEL: ${MINIMAX_MODEL_ID:-MiniMax-M2.7-highspeed}
       AGENT_TIMEOUT: ${AGENT_TIMEOUT:-30m}
       MAX_CONCURRENT_AGENTS: ${MAX_CONCURRENT_AGENTS:-8}
       DATA_DIR: /app/data