Expose `disableModelInvocation` on `session.skills_loaded` skill entries

Bắt đầu với schema sự kiện session.skills_loaded và các kiểu mục nhập theo từng skill, bao gồm SkillsLoadedSkill của Rust và kiểu dữ liệu session.skills_loaded của TypeScript. Sau đó, kiểm tra các cấu trúc discovery liên quan của Skill và ServerSkill, cùng với flag gọi model hiện có của producer. Được xem là hoàn tất khi mọi cấu trúc được liệt kê đều cung cấp disableModelInvocation và producer điền giá trị này bằng flag hiện có, trong khi các giá trị mặc định của producer cũ vẫn là false.

Summary

The session.skills_loaded event reports each skill's enabled and userInvocable flags, but not its model-invocation flag (the disable-model-invocation frontmatter gate). Please add disableModelInvocation to each skill entry so consumers can tell whether the model may auto-invoke a skill — not just whether the user can invoke it as a slash command.

Why

userInvocable (user slash-command availability) and model-invocability are two independent axes:

• userInvocable: true/false — can the user invoke it as a slash command.
• disableModelInvocation: true/false — may the model auto-invoke it.

A skill can be any combination (user-only, model-only, both). Consumers today only receive userInvocable, so they can't distinguish a model-auto-invoked skill from a user-only one. This matters for:

• Rendering an accurate command palette / skill list (which entries are slash commands vs. silently model-driven).
• Projecting skills into surfaces that have a native model-invocation concept (for example, AHP's SkillCustomization already has a disableModelInvocation field, which currently can't be populated from this event).

The flag is already part of the skill model — it's used internally to decide whether a skill is visible to the model — so this is a surfacing change, not new behavior.

Current shape

session.skills_loaded skill entries today (camelCase wire):

{
  "name": "…",
  "description": "…",
  "source": "project | inherited | personal-copilot | personal-agents | plugin | custom | builtin",
  "path": "…",            // optional
  "argumentHint": "…",    // optional
  "enabled": true,
  "userInvocable": true
}

Proposed change

Add disableModelInvocation: boolean to each entry:

{
  "name": "…",
  "description": "…",
  "source": "…",
  "path": "…",
  "argumentHint": "…",
  "enabled": true,
  "userInvocable": true,
  "disableModelInvocation": false   // NEW
}

Surfaces to touch:

• The session.skills_loaded event schema (the per-skill entry shape).
• Generated types in every language target (e.g. the Rust SkillsLoadedSkill and the TypeScript session.skills_loaded data type).
• For consistency, mirror the field onto the related skill API types that also omit it today (the Skill / ServerSkill discovery shapes).
• Populate it at the producer from the skill model's existing model-invocation flag.

Backwards compatibility

Additive boolean; existing consumers are unaffected. A sensible default for older producers is false (model invocation allowed), matching the default semantics of the disable-model-invocation frontmatter flag.