Slash skill commands do not reload edited SKILL.md content

Problem

When developing a project-local Skill, editing .opencode/skills/<name>/SKILL.md in VS Code is reflected in the file/Git diff, but invoking /<name> in OpenCode still uses the content loaded when the process started. Developers must restart OpenCode to test each Skill edit.

Reproduction

1. Start OpenCode with a project-local Skill.
2. Invoke /<skill-name> once.
3. Edit and save that Skill's SKILL.md.
4. Invoke /<skill-name> again.

The second invocation returns the old Skill body.

Expected behavior

Slash commands backed by Skills should reload the current SKILL.md content when invoked. Existing conversation output should remain immutable history.

Root cause

The Command service builds slash commands from skill.all() at initialization and closes over item.content, so /skill-name never reaches the Skill service again.

Why this is distinct

This is not about discovering Skills created after startup (#42478) or adding a general file-watching system (#8751, #34492). The Skill already exists and is listed correctly. Its disk-backed content can already be reloaded by Skill.require(), but the slash command path bypasses that reload by retaining the initial item.content snapshot.