feat: add required mode flag to cleanup and close

- Made `mode` a mandatory property in `MultiModelOptions`, `CloseSessionOptions`, and `CleanupOptions`.
- Updated function signatures to accept `mode` and removed default empty option objects where appropriate.
- Passed `mode: "cli"` from CLI commands and `mode: "tool"` from tool commands to cleanup, close, and open operations.
- Adjusted internal handling to use the provided `mode` (removed fallback defaults).
- Updated type definitions and added documentation for the new `mode` field.

src/cli.ts

@@ -78,6 +78,7 @@ program
           cleanupWorktrees: !options.keepWorktrees,
           force: options.force,
           createArchiveTags: options.tags,
+          mode: "cli",
         });
 
         if (result.success) {
@@ -107,6 +108,7 @@ program
       const result = await cleanupMultiModel({
         force: options.force,
         remote: options.remote === true ? undefined : options.remote,
+        mode: "cli",
       });
 
       if (result.success) {