refactor: add consumer-neutral CLI profiles

[codeforester]

What

• Add CliProfile with generic and temporary legacy Base policies.
• Move project discovery, configuration, runtime placement, history, and wrapper display decisions behind the profile boundary.
• Add a neutral runtime namespace and Context.application_home compatibility alias.
• Document the generic contract, compatibility behavior, and migration phases.

Why

base_cli is intended to be a standalone CLI lifecycle library, but App directly encoded Base manifest, config, cache, history, and delegation conventions.

Impact

Standalone consumers can opt into CliProfile.generic() with no implicit manifest, product-owned config, or history behavior. Existing App() callers retain historical Base behavior through CliProfile.legacy_base() while the Base repository migrates to an explicit adapter.

Root cause

Consumer-specific policy lived inside the generic application lifecycle instead of being injected at the boundary.

Checks

• 157 passed, 4 subtests passed
• ./tests/validate.sh
• git diff --check

Fixes #16

This is the first compatibility-preserving migration slice. Follow-up work will move the legacy Base adapter and remaining Base-shaped context/config/history types into the Base consumer. The package rename is intentionally out of scope.