Fix five aspire ls bugs from #17620 (L1–L5)

docs/specs/cli-output-formats.md

@@ -44,6 +44,8 @@ Use `--format json --stream` to receive discovery results as NDJSON, with one co
 {"path":"/path/to/ts-app/apphost.ts","language":"TypeScript","status":"possibly-unbuildable"}
 ```
 
+Stream output is emitted in arrival order from parallel discovery; lines are not sorted. The non-streaming `--format json` snapshot above is sorted by `path`. If you need a deterministic order for streamed output, pipe through your own sort step (for example `jq -s 'sort_by(.path)'`).
+
 If discovery finds no AppHost candidates, the stream emits no lines. The stream does not emit `started`, `complete`, or `canceled` control records; use the command's exit code and end-of-file to detect stream completion.
 
 #### AppHost candidate fields

src/Aspire.Cli/Commands/LsCommand.cs

@@ -153,15 +153,20 @@ private async Task<List<AppHostProjectCandidate>> FindAppHostsWithJsonStreamAsyn
     {
         var appHosts = new List<AppHostProjectCandidate>();
 
+        // `aspire ls --format json --stream` emits each candidate as soon as discovery surfaces
+        // it (arrival order from parallel discovery). The contract is documented in
+        // docs/specs/cli-output-formats.md. Do NOT sort here:
+        // candidates have already been written to stdout via WriteJsonStreamCandidate above, so
+        // any post-loop sort would only reorder this in-memory list — which the caller does not
+        // use for stream output. Pipe to `sort` / `jq -s 'sort_by(.path)'` for ordered output.
+        // See https://github.com/microsoft/aspire/issues/17621.
         await foreach (var candidate in _projectLocator.FindAppHostProjectsStreamAsync(_executionContext.WorkingDirectory, scope, cancellationToken: cancellationToken).ConfigureAwait(false))
         {
             cancellationToken.ThrowIfCancellationRequested();
             appHosts.Add(candidate);
             WriteJsonStreamCandidate(CreateDisplayInfo(candidate));
         }
 
-        appHosts.Sort((x, y) => string.Compare(x.AppHostFile.FullName, y.AppHostFile.FullName, StringComparison.Ordinal));
-
         return appHosts;
     }
 

src/Aspire.Cli/Program.cs

@@ -304,7 +304,7 @@ internal static async Task<IHost> BuildApplicationAsync(string[] args, CliStartu
         var globalSettingsFilePath = GetGlobalSettingsPath(startupContext.Logger);
         var globalSettingsFile = new FileInfo(globalSettingsFilePath);
         var workingDirectory = new DirectoryInfo(Environment.CurrentDirectory);
-        ConfigurationHelper.RegisterSettingsFiles(builder.Configuration, workingDirectory, globalSettingsFile, startupContext.Logger);
+        ConfigurationHelper.RegisterSettingsFiles(builder.Configuration, workingDirectory, globalSettingsFile);
 
         TrySetLocaleOverride(LocaleHelpers.GetLocaleOverride(builder.Configuration), startupContext.Logger, startupContext.ErrorWriter);
         WarnIfGlobalSettingsContainAppHostPath(globalSettingsFile, startupContext.ErrorWriter);

src/Aspire.Cli/Resources/ErrorStrings.resx

@@ -276,4 +276,16 @@
   <data name="CodegenDebugHeader" xml:space="preserve">
     <value>Diagnostic details:</value>
   </data>
+  <data name="ConfiguredAppHostPathHasInvalidCharacters" xml:space="preserve">
+    <value>The configured AppHost path in '{0}' ('{1}') is empty or contains characters that are not allowed in a file path.</value>
+    <comment>{0} is the configuration file path that the user authored, {1} is the field/setting name within that file (for example "appHost.path" or "appHostPath")</comment>
+  </data>
+  <data name="ConfiguredAppHostPathMustBeString" xml:space="preserve">
+    <value>The configured AppHost path in '{0}' ('{1}') must be a JSON string.</value>
+    <comment>{0} is the configuration file path that the user authored, {1} is the field/setting name within that file (for example "appHost.path" or "appHostPath")</comment>
+  </data>
+  <data name="ConfigurationFileMustBeJsonObject" xml:space="preserve">
+    <value>The configuration file '{0}' must contain a JSON object.</value>
+    <comment>{0} is the configuration file path that the user authored.</comment>
+  </data>
 </root>

src/Aspire.Cli/Resources/SharedCommandStrings.resx

@@ -152,7 +152,7 @@
     <value>Include all candidate AppHosts, ignoring .gitignore and built-in directory filters</value>
   </data>
   <data name="LsStreamOptionDescription" xml:space="preserve">
-    <value>Stream newline-delimited JSON discovery events. Requires --format json</value>
+    <value>Output discovered AppHosts as newline-delimited JSON. Requires --format json</value>
   </data>
   <data name="LsStreamRequiresJson" xml:space="preserve">
     <value>The --stream option requires --format json.</value>