fix: FileFilter must check exclude_dirs before the endswith shortcut

[LeSingh1]

When an explicit path (e.g. .dotted or ext/ext.jpg) is listed in
--reload-include, FileFilter.__call__ matched via path.match()
and then hit the str(path).endswith(include_pattern) shortcut, which
returned True immediately. The early return skipped the loop that
checks exclude_dirs, so any file whose name exactly matched an include
pattern was watched even when it lived inside a directory listed in
--reload-exclude.

The endswith shortcut was added in c55af77 to let hidden/dotted files
and other non-glob entries bypass the pattern-level excludes (e.g.
.*). That intent is correct; the mistake is that it also bypassed
directory-level excludes, which is a stronger signal from the user.

The fix moves the exclude_dirs loop above the endswith shortcut so
that directory exclusions are always evaluated first. Files that match
an exact include pattern but reside under an excluded directory are now
rejected, while files outside excluded directories continue to bypass
the pattern excludes as before.

A new unit test (pure FileFilter instantiation, no file-system
watcher) reproduces the bug and confirms the fix: it asserts that
vendor/.dotted is not watched when .dotted is in --reload-include
and vendor/ is in --reload-exclude.

[codspeed-hq]

Merging this PR will not alter performance

✅ 24 untouched benchmarks

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_{Comparing LeSingh1:fix/file-filter-exclude-dirs-before-endswith (98f80fb) with main (e8a31bc)}

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}