Remove no-files-matched warning from copy-by-pattern

Empty matches are not inherently wrong — patterns may be intentionally
optional. Silently return 0 instead of emitting a warning.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: alfonso-noriega

packages/app/src/cli/services/build/steps/include-assets-step.test.ts

@@ -535,7 +535,6 @@ describe('executeIncludeAssetsStep', () => {
 
       // Then
       expect(result.filesCopied).toBe(0)
-      expect(mockStdout.write).toHaveBeenCalledWith(expect.stringContaining('no files matched'))
     })
   })
 

packages/app/src/cli/services/build/steps/include-assets/copy-by-pattern.test.ts

@@ -54,7 +54,6 @@ describe('copyByPattern', () => {
     expect(result).toBe(0)
     expect(fs.mkdir).not.toHaveBeenCalled()
     expect(fs.copyFile).not.toHaveBeenCalled()
-    expect(mockStdout.write).toHaveBeenCalledWith(expect.stringContaining('no files matched'))
   })
 
   test('skips file and warns when resolved destination escapes the output directory', async () => {

packages/app/src/cli/services/build/steps/include-assets/copy-by-pattern.ts

@@ -21,7 +21,6 @@ export async function copyByPattern(
   })
 
   if (files.length === 0) {
-    options.stdout.write(`Warning: no files matched, skipping\n`)
     return 0
   }