[Bug] Tree mode ignores -n and --limit

[equationzhao]

Describe the bug
-n 2 limits normal listing output to two entries. In tree mode, the same limit is ignored and all entries are printed.

To Reproduce

1. Build the current repository:

go build -o /tmp/g-bug-audit .

2. Create three files:

tmp=$(mktemp -d)
touch "$tmp/a" "$tmp/b" "$tmp/c"

3. Run tree mode with a limit:

/tmp/g-bug-audit --no-config --disable-index --classic -A -T -n 2 "$tmp"
printf 'exit=%s tmp=%s\n' $? "$tmp"

4. Actual output:

�[2m�[0mtmp.iWrYpNVtid
�[2m├── �[0ma
�[2m├── �[0mb
�[2m╰── �[0mc
exit=0 tmp=/var/folders/1b/57vdxmgj7s1glqm6tbsw1frm0000gn/T/tmp.iWrYpNVtid

5. Control check with normal listing:

/tmp/g-bug-audit --no-config --disable-index --classic -A --byline -n 2 "$tmp"

Actual control output:

a
b
exit=0 tmp=/var/folders/1b/57vdxmgj7s1glqm6tbsw1frm0000gn/T/tmp.AEO3T7hoWn

6. Expected output: tree mode should either honor -n 2 consistently or reject the combination with an explicit error.

Screenshots
Not applicable.

Info (please complete the following information):

• OS: macOS darwin/arm64
• Version: v0.31.2, Go go1.26.1

Additional context
The limit appears to be applied only when tree mode is not active, so tree mode silently ignores a user-specified limit.