Merge main into feat/exec-agent to pick up ba1ab6e which added
matrix_send_ctx to lib/env.sh and action/action-agent.sh. Without
this merge, CI smoke test fails on the PR merge commit.
Re-applied exec changes on top of main:
- .env.example, AGENTS.md, bin/disinto, lib/matrix_listener.sh
- .woodpecker/agent-smoke.sh: exec scripts added to checks