Reach: AMI product + EC2 Image Builder component

[fheikens]

Part of #233. Inherits the cross-cutting decisions from #233 (read it; do not
duplicate here).

What

Publish the Signals collector as a separate AmiProduct@1.0 (server) listing
and expose it as a reusable EC2 Image Builder component, per
https://aws.amazon.com/blogs/awsmarketplace/boost-your-softwares-reach-with-aws-marketplace-and-ec2-image-builder-integration/
(the integration is AMI-only — it does not attach to our container product).

Why plausible for Signals

Signals already ships an EC2 deploy path (deploy/aws, the bundled EC2
instance), so packaging the collector into an AMI / Image Builder component is
more feasible than for a pure-container ISV. Reaches customers baking golden
AMIs who want the collector pre-installed.

Scope (larger — separate product)

• Stand up an AmiProduct@1.0 listing (separate from the container product).
• Build + maintain the AMI, and author the Image Builder component YAML.
• start-change-set with ComponentArn + AccessRoleArn, then visibility.
• Its own onboarding/review.

Acceptance criteria

• A Signals AMI/server product is discoverable in EC2 Image Builder.
• Component installs + configures the collector during AMI bake.

Gate

Only pursue if there is real demand for non-container, EC2-baked deployment.
Decision gated on #233.