Fix --fix-fuzzy to work with fuzzy-only files and handle fuzzy headers

[pescheck-bram]

Problem

• --fix-fuzzy was skipping files that had fuzzy entries but no untranslated entries
• Fuzzy headers (#, fuzzy before msgid "") weren't being handled, causing Django/gettext to ignore entire catalogs
• Entry counting showed negative numbers in fix-fuzzy mode

Solution

• Files with fuzzy entries are now processed even without untranslated entries
• Removes fuzzy flags from PO file headers that would invalidate the entire catalog
• Fixed progress tracking to count fuzzy entries correctly
• Updated display to show "FUZZY FIX RESULTS" with accurate statistics

Changes

• Modified _scan_po_files() to detect fuzzy entries when --fix-fuzzy is enabled
• Updated fix_fuzzy_entries() to handle metadata_is_fuzzy for headers
• Fixed _track_file_progress() and summary display for fuzzy mode