Revert util.js empty hash handling - hash files should always exist in production

- Remove graceful handling of missing hash directories in util.js
- Hash files are generated by build process and should always be present
- Missing hash files indicate build failure, not normal operation
- Update README to clarify hash files are required for production
- Keep mock hash file creation instructions for testing only

Author: azure-pipelines-bot

release/README.md

@@ -31,7 +31,8 @@ npm audit fix --force
 #### A. Test `fillReleaseNotesTemplate.js`
 
 ```bash
-# Create mock hash files (scripts expect these)
+# Create mock hash files for testing (required - scripts expect these to exist)
+# Note: In production builds, these are generated automatically by the build process
 mkdir -p ../_hashes/hash
 echo "abcd1234567890abcd1234567890abcd1234567890abcd1234567890abcd1234" > ../_hashes/hash/vsts-agent-win-x64-3.999.999.zip.sha256
 echo "efgh1234567890efgh1234567890efgh1234567890efgh1234567890efgh1234" > ../_hashes/hash/vsts-agent-osx-x64-3.999.999.tar.gz.sha256
@@ -131,8 +132,9 @@ if (dryrun) {
 Some scripts expect certain directories/files to exist:
 
 ```bash
-# For hash-related scripts
+# For hash-related scripts (REQUIRED - scripts will fail without these)
 mkdir -p ../_hashes/hash
+# Create mock hash files for testing as shown in fillReleaseNotesTemplate.js section
 
 # For integration file generation
 mkdir -p ../_layout/integrations
@@ -165,8 +167,9 @@ After testing locally, verify the pipeline still works by running a test build.
 ### Common Error Messages
 
 1. **"ENOENT: no such file or directory, scandir"**
-   - Missing `_hashes` directory
-   - Solution: Create mock hash files as shown above
+   - Missing `_hashes` directory or hash files
+   - **For testing**: Create mock hash files as shown above
+   - **For production**: Hash files should be generated by the build process - this indicates a build failure
 
 2. **"got.get is not a function"** 
    - Package API changed

release/util.js

@@ -89,20 +89,7 @@ exports.fillAgentParameters = function(template, destination, version)
  */
 exports.getHashes = function() {
     const hashesDirPath = path.join(__dirname, '..', '_hashes', 'hash');
-    
-    // Check if hash directory exists
-    if (!fs.existsSync(hashesDirPath)) {
-        console.log(`Warning: Hash directory ${hashesDirPath} does not exist. Using empty hashes.`);
-        return {};
-    }
-    
-    let hashFiles;
-    try {
-        hashFiles = fs.readdirSync(hashesDirPath);
-    } catch (error) {
-        console.log(`Warning: Could not read hash directory ${hashesDirPath}: ${error.message}. Using empty hashes.`);
-        return {};
-    }
+    const hashFiles = fs.readdirSync(hashesDirPath);
 
     const hashes = {};
     for (const hashFileName of hashFiles) {