feat(ai-setup): generate .agents skills for agents target across hosts

- write .agents/skills/<skill>/SKILL.md when agents target is selected

- apply parity updates in MCP, VS Code extension, and Obsidian plugin

- add/extend ai-setup tests for agents skill generation

mcp-ts/src/aisetup.ts

@@ -2,7 +2,8 @@
  * AI instruction file generation for Bindery (MCP server).
  *
  * Generates CLAUDE.md, .github/copilot-instructions.md, .cursor/rules,
- * AGENTS.md, and .claude/skills/<skill>/SKILL.md from the book's
+ * AGENTS.md, and skills under .claude/skills/<skill>/SKILL.md and
+ * .agents/skills/<skill>/SKILL.md from the book's
  * .bindery/settings.json.
  *
  * Template content is maintained in bindery-core/src/templates/*.ts
@@ -169,6 +170,10 @@ export function setupAiFiles(options: AiSetupOptions): AiSetupResult {
                 break;
             case 'agents':
                 writeFile(root, 'AGENTS.md', renderTemplate('agents', ctx), overwrite, versionFile, result);
+                for (const skill of skills) {
+                    const skillMd = path.join('.agents', 'skills', skill, 'SKILL.md');
+                    writeFile(root, skillMd, renderTemplate(skill, ctx), overwrite, versionFile, result);
+                }
                 break;
         }
     }

mcp-ts/test/aisetup.test.ts

@@ -98,4 +98,25 @@ describe('setupAiFiles skill generation', () => {
     expect(result.skillZipManifest.created).toEqual([]);
     expect(fs.readFileSync(path.join(root, '.claude', 'skills', 'read-aloud.zip'), 'utf-8')).toBe('legacy zip bytes');
   });
+
+  it('generates requested skill markdown files for agents target under .agents/skills', async () => {
+    const { setupAiFiles } = await loadAiSetup();
+
+    const root = makeRoot();
+    write(path.join(root, '.bindery', 'settings.json'), JSON.stringify({
+      bookTitle: 'Test Book',
+      storyFolder: 'Story',
+      languages: [{ code: 'EN', folderName: 'EN' }],
+    }, null, 2) + '\n');
+
+    const result = setupAiFiles({
+      root,
+      targets: ['agents'],
+      skills: ['read-in'],
+      overwrite: true,
+    });
+
+    expect(result.regenerated).toContain('.agents/skills/read-in/SKILL.md');
+    expect(fs.existsSync(path.join(root, '.agents', 'skills', 'read-in', 'SKILL.md'))).toBe(true);
+  });
 });

obsidian-plugin/src/ai-setup.ts

@@ -2,7 +2,7 @@
  * Obsidian-specific AI setup wrapper.
  *
  * Generates AI instruction files (CLAUDE.md, copilot-instructions.md, .cursor/rules, AGENTS.md)
- * and Claude skill templates from the book's .bindery/settings.json.
+ * and skill templates from the book's .bindery/settings.json.
  *
  * For Obsidian, this is a simpler adaptation since we don't have the VS Code LM API,
  * so we just generate the files to the filesystem directly.
@@ -89,6 +89,10 @@ export function setupAiFiles(
                 break;
             case 'agents':
                 writeFile(bookRoot, 'AGENTS.md', renderTemplate('agents', ctx), overwrite, result);
+                for (const skill of skills) {
+                    const skillDir = path.join('.agents', 'skills', skill);
+                    writeFile(bookRoot, path.join(skillDir, 'SKILL.md'), renderTemplate(skill, ctx), overwrite, result);
+                }
                 break;
         }
     }

obsidian-plugin/test/ai-setup.test.ts

@@ -85,6 +85,22 @@ describe('AI Setup', () => {
         expect(fs.existsSync(agentsPath)).toBe(true);
     });
 
+    it('should create skill markdown files under .agents/skills when agents target requested', async () => {
+        const settingsPath = path.join(tempRoot, '.bindery', 'settings.json');
+        fs.mkdirSync(path.dirname(settingsPath), { recursive: true });
+        fs.writeFileSync(settingsPath, JSON.stringify({
+            bookTitle: 'Test Book',
+        }, null, 2), 'utf-8');
+
+        await setupAiFiles(mockApp, tempRoot, ['agents'], ['read-in', 'review'], false);
+
+        const readInSkillPath = path.join(tempRoot, '.agents', 'skills', 'read-in', 'SKILL.md');
+        const reviewSkillPath = path.join(tempRoot, '.agents', 'skills', 'review', 'SKILL.md');
+
+        expect(fs.existsSync(readInSkillPath)).toBe(true);
+        expect(fs.existsSync(reviewSkillPath)).toBe(true);
+    });
+
     it('should skip existing files when overwrite is false', async () => {
         const settingsPath = path.join(tempRoot, '.bindery', 'settings.json');
         fs.mkdirSync(path.dirname(settingsPath), { recursive: true });

vscode-ext/src/ai-setup.ts

@@ -7,7 +7,7 @@
  *   claude    → CLAUDE.md + .claude/skills/<skill>/SKILL.md
  *   copilot   → .github/copilot-instructions.md
  *   cursor    → .cursor/rules
- *   agents    → AGENTS.md  (OpenAI Agents, Aider, Codex, etc.)
+ *   agents    → AGENTS.md + .agents/skills/<skill>/SKILL.md (OpenAI Agents, Aider, Codex, etc.)
  *
  * Templates and TemplateContext live in @bindery/core (single source of truth).
  */
@@ -92,6 +92,10 @@ export function setupAiFiles(options: AiSetupOptions): AiSetupResult {
 
             case 'agents':
                 writeFile(root, 'AGENTS.md', renderTemplate('agents', ctx), overwrite, result);
+                for (const skill of skills) {
+                    const skillDir = path.join('.agents', 'skills', skill);
+                    writeFile(root, path.join(skillDir, 'SKILL.md'), renderTemplate(skill, ctx), overwrite, result);
+                }
                 break;
         }
     }