docs: complete XML doc coverage (returns, summaries, inheritdoc)

Resolve all 622 issues flagged by the enhanced CommentChecker: add missing
<returns> tags (incl. the standard phrasing on non-generic Task methods),
add missing <summary> tags, and replace misused/redundant <inheritdoc/> on
members that override or implement nothing with real documentation.
Documentation-only — no behavior change; solution builds clean.

src/ZB.MOM.WW.ScadaBridge.CentralUI/ScriptAnalysis/SandboxConsoleCapture.cs

@@ -41,6 +41,7 @@ internal sealed class SandboxConsoleCapture : TextWriter
     /// <see cref="Console.Error"/> once for the process. Idempotent and
     /// thread-safe. Subsequent calls return the already-installed instances.
     /// </summary>
+    /// <returns>The installed <see cref="SandboxConsoleCapture"/> instances for stdout and stderr.</returns>
     public static (SandboxConsoleCapture Out, SandboxConsoleCapture Error) Install()
     {
         if (_outInstance != null && _errorInstance != null)
@@ -72,6 +73,7 @@ internal sealed class SandboxConsoleCapture : TextWriter
     /// other call-trees are unaffected.
     /// </summary>
     /// <param name="buffer">The writer that receives console output for this scope.</param>
+    /// <returns>A <see cref="CaptureScope"/> that, when disposed, restores the previous capture state.</returns>
     public CaptureScope BeginCapture(StringWriter buffer)
     {
         var previous = _current.Value;