[Feature Request] Add project-level configuration to disable global skills/commands

Bug Description
Title: Add per-project setting to disable global skills/commands

Description:
When working in a project with local skills/commands that override global ones,
the autocomplete shows both versions, which creates confusion about which will execute.

Current behavior:

• Both global and project-level skills appear in autocomplete
• Example: /create-plan shows twice (global skill + project command)

Requested feature:
Add a project setting to disable specific global skills/commands:

{
"disabledGlobalSkills": ["skill-a", "skill-b"],
"disabledGlobalCommands": ["command-a", "command-b"]
}

This would:

1. Hide disabled global skills from autocomplete in that project
2. Ensure only project-level versions appear
3. Keep global skills available in other projects

Use case: Teams want project-specific versions without removing global
versions that are useful in other projects.

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.5
• Feedback ID: 1167fee8-bd44-4a05-a42d-91270fba0c30

Errors