fix: normalize Windows backslash paths in file uploads
When uploading files from a Windows client to a Linux server,
file paths containing backslashes were not being properly interpreted as
directory separators. This caused files intended for subdirectories to be
created in the root directory with backslashes in their filenames.
Changes:
- Add util.CleanWindowsPath and util.CleanWindowsPathBase helper functions
in weed/util/fullpath.go for reusable path normalization
- Use path.Join/path.Clean/path.Base instead of filepath equivalents
for URL path semantics (filepath is OS-specific)
- Apply normalization in weed admin handlers and filer upload parsing
Fixes#7628
* fix: disallow file name too long when writing a file
* bool LongerName to MaxFilenameLength
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Co-authored-by: Konstantin Lebedev <9497591+kmlebedev@users.noreply.github.co>
