Demonstrate consumer profiles and configuration policy boundaries

[codeforester]

Summary

Show how a real consumer supplies project discovery, configuration, runtime, and history policy without coupling those policies into base-cli.

Scope

• Add a small consumer-owned configuration model with validation.
• Use an explicit CliProfile or equivalent public extension boundary.
• Show configuration provenance and safe handling of invalid configuration.
• Include one generic-profile path and one consumer-specific policy path.

Acceptance criteria

• The example uses only supported public Base-CLI APIs.
• The README identifies which policy is owned by the consumer.
• Tests cover valid, missing, and invalid configuration cases.

Non-goals

Do not invent a repository manifest convention or make Base-specific configuration mandatory.