fix(stdout): print the displayed item count with --show-item-count

[LuisFigueroaG]

With -n -C the item count depended on how the tree was scanned. The default scan printed 3 for a directory with three items and 0 for an empty one. --sequential, multiple paths, and -f input printed 4 and 1, because stdout printed the raw GetItemCount(), which includes the directory itself.

stdout now prints fs.DisplayedItemCount like the TUI and web UI (ADR 0001). The top-dir analyzer used by default in non-interactive mode now uses the same raw counts as Dir (a directory includes itself, files count 1), so the displayed value is the same for every analyzer.

Added a test that runs the same tree through the top-dir, parallel and sequential analyzers. make lint and go test ./... pass.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.73%. Comparing base (387cf50) to head (9650e5f).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #691   +/-   ##
=======================================
  Coverage   90.73%   90.73%           
=======================================
  Files          76       76           
  Lines        6843     6844    +1     
=======================================
+ Hits         6209     6210    +1     
  Misses        633      633           
  Partials        1        1           

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[LuisFigueroaG]

The lint failure isn't from this change: golangci-lint v2.13.2 can't load go1.27.2 export data (export data version 5 is greater than maximum supported version 4), and setup-go picks up go1.27.2 for 1.27.x now. It fails the same way on master locally, and other recent PRs hit it too, while v2.15.0 runs clean. Bumping the version in test.yml (and the Makefile) should fix it for all open PRs.