refactor(skills): centralize install action modes

src/cli/skills.test.ts

@@ -17,6 +17,8 @@ import {
   renderSkillInstallPreflight,
   toSkillInstallerExecutionStubView,
   renderSkillInstallerExecutionStub,
+  toSkillInstallerExecutionStubFromPreflight,
+  runSkillInstallAction,
 } from './skills.js';
 import type { Skill } from '../skills/index.js';
 
@@ -247,6 +249,21 @@ describe('skills CLI helpers', () => {
     expect(output).toContain('Skipped:');
   });
 
+  it('derives execution stub view from preflight data', () => {
+    const preflight = {
+      sourcePath: '/tmp/source-skill',
+      skill: { name: 'exec-stub', tier: 'managed' as const, version: '1.0.0' },
+      mode: 'dry-run' as const,
+      steps: [{ installerType: 'download', command: 'download https://example.com/a.tgz -> /tmp/a.tgz' }],
+      skipped: [],
+    };
+
+    const view = toSkillInstallerExecutionStubFromPreflight(preflight);
+
+    expect(view.execution).toBe('stub');
+    expect(view.wouldRun).toEqual(['download https://example.com/a.tgz -> /tmp/a.tgz']);
+  });
+
   it('summarizes refresh counts across status and tiers', () => {
     const summary = summarizeSkillsRefresh([
       buildSkill({ manifest: { name: 'a', description: 'a', version: '1.0.0', tier: 'bundled' } }),
@@ -306,6 +323,27 @@ describe('skills CLI helpers', () => {
     rmSync(root, { recursive: true, force: true });
   });
 
+  it('supports plan-only install action mode without installing', () => {
+    const root = mkdtempSync(join(tmpdir(), 'flynn-skills-cli-'));
+    const sourceDir = join(root, 'source-skill');
+    const managedDir = join(root, 'managed');
+    mkdirSync(sourceDir, { recursive: true });
+    writeFileSync(join(sourceDir, 'SKILL.md'), '# Plan Skill\nInstructions');
+    writeFileSync(
+      join(sourceDir, 'manifest.json'),
+      JSON.stringify({ name: 'plan-skill', description: 'Plan only', version: '1.0.0' }),
+      'utf-8',
+    );
+
+    const installer = new SkillInstaller(managedDir);
+    const result = runSkillInstallAction(installer, sourceDir, { mode: 'plan-only', asJson: false });
+
+    expect(result.ok).toBe(true);
+    expect(existsSync(join(managedDir, 'plan-skill', 'SKILL.md'))).toBe(false);
+
+    rmSync(root, { recursive: true, force: true });
+  });
+
   it('requires --yes confirmation for uninstall helper', () => {
     const root = mkdtempSync(join(tmpdir(), 'flynn-skills-cli-'));
     const installer = new SkillInstaller(join(root, 'managed'));