feat(skills): reload registry on watcher change events

src/skills/registry.test.ts

@@ -106,6 +106,23 @@ describe('SkillRegistry', () => {
     expect(registry.unregister('ghost')).toBe(false);
   });
 
+  it('reset replaces all existing skills with a new set', () => {
+    const registry = new SkillRegistry();
+    registry.register(makeSkill({ name: 'old-one' }));
+    registry.register(makeSkill({ name: 'old-two' }));
+
+    registry.reset([
+      makeSkill({ name: 'new-one' }),
+      makeSkill({ name: 'new-two', available: false }),
+    ]);
+
+    expect(registry.get('old-one')).toBeUndefined();
+    expect(registry.get('old-two')).toBeUndefined();
+    expect(registry.get('new-one')).toBeDefined();
+    expect(registry.get('new-two')).toBeDefined();
+    expect(registry.list()).toHaveLength(2);
+  });
+
   it('getSystemPromptAdditions returns empty string with no skills', () => {
     // Negative: with nothing registered the prompt additions should be empty.
     const registry = new SkillRegistry();

src/skills/registry.ts

@@ -9,6 +9,14 @@ import type { Skill } from './types.js';
 export class SkillRegistry {
   private skills: Map<string, Skill> = new Map();
 
+  /** Replace all registered skills with the provided set. */
+  reset(skills: Skill[]): void {
+    this.skills.clear();
+    for (const skill of skills) {
+      this.skills.set(skill.manifest.name, skill);
+    }
+  }
+
   /** Register a skill. Replaces any existing skill with the same name. */
   register(skill: Skill): void {
     this.skills.set(skill.manifest.name, skill);