Allow permission profiles to extend multiple profiles

What variant of Codex are you using?

app

What feature would you like to see?

Problem

Permission profiles currently support only one parent:

extends = "profile-a"

This limits reuse when a profile needs permissions from several independent profiles. Users must duplicate rules or create artificial inheritance chains.

Proposal

Allow extends to accept an array:

extends = ["profile-a", "profile-b"]

The existing scalar syntax should remain supported.

The implementation should define:

• merge order and conflict handling;
• recursive inheritance;
• cycle detection; and
• duplicate-parent behavior.

An alternative would be a separate composition field such as:

includes = ["profile-a", "profile-b"]

Related work

• #22270 introduced single-parent profile inheritance.
• #23705 applied inherited profiles at runtime.
• #13496 demonstrates additive permission composition internally for skills.

This would make permission profiles more modular and avoid maintaining separate profiles for every combination of permissions.

Additional information

_No response_