chore: prepare layer catalog

[ava-silver]

What does this PR do?

• Adds generated runtime, normalization, and architecture maps.
• Derives the plugin's existing lookups from those maps.
• Keeps the commercial and GovCloud ARN files unchanged.

Motivation

Prepare the plugin for centralized Lambda catalog updates without changing layer selection or disrupting the existing ARN generator.

Testing Guidelines

No manual validation.

Additional Notes

The future renderer owns runtime-catalog.json, layers.json, and layers-gov.json as one artifact set.

Types of changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog

[ava-silver]

• chore: retire layer generator #727
• test: define unsupported runtime boundaries #726
• chore: prepare layer catalog #725 👈 (View in Graphite)
• main

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