Flow release notes

The first public release, published under its original name, Emberwire.

• A 25.1 MB image for amd64 and arm64, with 51 node types and roughly 30,000 lines of Go in one static binary.
• Flow files stay Node-RED v1 compatible. Point it at a flows.json and it runs.
• Every inbox is bounded, with a policy per node: block, drop the newest, drop the oldest, or raise it to a Catch node.
• The race detector is clean on every package.

This release is Apache-2.0 and stays that way. It is published today as Emberwire, and the HotLoop Flow release is coming.