Wrap FILES section paths in .nf/.fi to suppress groff line-adjustment warnings

The FILES section emits long glob patterns like
~/.config/station/{*.toml,*.yaml,...,pyproject.toml} as a single italic token.
In fill mode (the default after .SH), groff tries to justify the line and
emits "cannot adjust line" when the token is wider than the text area. This
caused test_generated_roff_passes_groff_lint to fail on ubuntu-24.04-arm for
both the station and forecast fixtures.

Wrapping each path in .nf/.fi (no-fill/restore) tells troff not to adjust
these lines, matching the same treatment used for \b-marked help text. The
separator between multiple entries is changed from .br to .sp for better
vertical spacing in no-fill mode.

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

Author: kdeldycke

click_extra/man_page.py

@@ -358,8 +358,10 @@ def to_roff(self) -> str:
             lines.append(".SH FILES")
             for index, path in enumerate(self.files):
                 if index > 0:
-                    lines.append(".br")
+                    lines.append(".sp")
+                lines.append(".nf")
                 lines.append(_italic(path))
+                lines.append(".fi")
 
         if self.exit_status:
             lines.append('.SH "EXIT STATUS"')