fix(stdout): --depth ignores --show-apparent-size when sorting

[VXNCXNX]

With --depth, children are sorted by disk usage even when --show-apparent-size is set, so the rows print out of order against the sizes shown next to them. A directory holding a 50M sparse file next to one with a 5M dense file:

$ gdu -np -a --depth 1 DIR

before    55.0 MiB DIR
           5.0 MiB DIR/realdir
          50.0 MiB DIR/sparsedir     <- larger, printed last

after     55.0 MiB DIR
          50.0 MiB DIR/sparsedir
           5.0 MiB DIR/realdir

showDir already picks SortByApparentSize when the flag is set, but printDirWithDepth hardcoded SortBySize. The selection now lives in a small sortSettings helper that both call, so they cannot drift again. Without -a the output is byte-identical to before, which I checked separately.

Test added in stdout_test.go; reverting the sort field fails it with "largest apparent size should be printed first". go test ./... passes, 18 packages. gofmt and vet clean.

AI disclosure: written with Claude Code. I ran the binary before and after against a sparse file and checked the mutation myself.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.04%. Comparing base (a313834) to head (4f8739c).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #630   +/-   ##
=======================================
  Coverage   87.04%   87.04%           
=======================================
  Files          69       69           
  Lines        7211     7211           
=======================================
  Hits         6277     6277           
  Misses        718      718           
  Partials      216      216           

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