Audit docs for agent-friendly Slide Spec authoring

[lreading]

Summary

Do a focused pass on the docs from the perspective of an AI coding agent or automation authoring Slide Spec content.

Things to check:

• The core file order is easy to discover.
• Schema docs and examples give enough information to generate valid YAML.
• llms.txt points to the right high-signal pages.
• Docs explain manual generated.yaml authoring and connector-produced data clearly.

Alternatives considered

Existing docs and llms.txt may already be close; this issue is for a short v1 audit and any small fixes that fall out of it.

Affected packages

• app (presentation renderer)
• cli (@slide-spec/cli)
• docs (documentation site)
• shared (types and validation)
• Unsure