feat(who): filter unresolved discussions to open entities only

Workload and active modes now exclude discussions on closed issues and
merged/closed MRs by default. Adds --include-closed flag to restore
the previous behavior when needed.

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

src/cli/autocorrect.rs

@@ -193,6 +193,7 @@ const COMMAND_FLAGS: &[(&str, &[&str])] = &[
             "--as-of",
             "--explain-score",
             "--include-bots",
+            "--include-closed",
             "--all-history",
         ],
     ),