2cffcc46c5
FW-04: mqtt_common.py now loads .env at module import via _load_dotenv(). Walks up from script dir to find workspace .env, sets vars not already in os.environ (OS env takes precedence). Uses stdlib only — no python-dotenv dependency. FW-06: bash wrapper sets trap EXIT before tmux new-session to publish error event if agent bootstrap fails (non-zero exit). Trap is cleared after successful session creation. Only active when job_id is set.