fix(agent): 将 pi-agent 默认模型对齐为 MiniMax-M2.7-highspeed

根因是 Go 默认 provider 误为 cc-switch-kimi-for-coding，且 app 容器未注入 PI_AGENT_*，导致 runner 收到未知 provider。

Co-authored-by: Cursor <cursoragent@cursor.com>

docker-compose.dev.yml

@@ -56,7 +56,7 @@ services:
       DATA_DIR: /app/data/workspaces
       MINIMAX_ENDPOINT_URL: ${MINIMAX_ENDPOINT_URL:-https://api.minimaxi.com/v1}
       MINIMAX_API_KEY: ${MINIMAX_API_KEY:-}
-      MINIMAX_MODEL_ID: ${MINIMAX_MODEL_ID:-MiniMax-M3}
+      MINIMAX_MODEL_ID: ${MINIMAX_MODEL_ID:-MiniMax-M2.7-highspeed}
       MINIMAX_API_TYPE: ${MINIMAX_API_TYPE:-openai-compatible}
       MINIMAX_PROVIDER: minimax
       TAVILY_API_KEYS: ${TAVILY_API_KEYS:-}
@@ -102,6 +102,8 @@ services:
       CURSOR_RUNNER_URL: http://cursor-agent:18765
       PI_AGENT_RUNNER_URL: http://pi-agent:18865
       PI_AGENT_RUNNER_AUTH_TOKEN: ${RUNNER_AUTH_TOKEN:-}
+      PI_AGENT_PROVIDER: ${PI_AGENT_PROVIDER:-minimax}
+      PI_AGENT_MODEL: ${PI_AGENT_MODEL:-MiniMax-M2.7-highspeed}
       RUNNER_AUTH_TOKEN: ${RUNNER_AUTH_TOKEN:-}
       ALLOW_IN_MEMORY: "false"
       AUX_FILE_DSN: file:/var/lib/feishu/outbox_dev.db?_journal_mode=WAL&_busy_timeout=5000