Metadata++ v2.0

Several BUG fixes and a couple of updates: cover chooser and synopsis-description chooser.

🐞 Bug Fixes
Fixed title matching for books with series/edition suffixes
Improved title normalization by stripping series/volume metadata before fuzzy matching.
Added prefix-based fallback matching.
Eliminated unnecessary duplicate browser fetches caused by failed merges.
Fixed incorrect synopsis language selection
Added lightweight language detection to synopsis scoring.
Descriptions now prefer the book's language instead of higher-weight sources containing translated or original-language summaries.
Fixed incorrect metadata from similarly titled books
Improved fuzzy title matching using stricter Jaccard word similarity.
Added author-validation veto to reject metadata from books with mismatching authors.
Fixed incorrect title and tags prioritization
Titles are now selected by highest similarity to the requested book rather than source weight.
Tags from weak title matches are discarded, preventing unrelated categories from contaminating metadata.
Fixed cover replacement logic
Improved existing-cover detection across all supported Calibre versions.
Prevented high-quality covers from being replaced by lower-quality thumbnails.
Added support for additional JPEG formats and Pillow fallback when image dimensions cannot be read.
Fixed cover quality evaluation
Prevented padded, letterboxed and placeholder covers from replacing superior existing covers.
Improved HTTP probing with HEAD → Range GET → GET fallback for CDN compatibility.
Removed premature cover-selection stopping, allowing all candidates to be evaluated before choosing the best one.

✨ New Features
Cover Chooser
Browse every discovered cover candidate before applying metadata.
Preview covers with source information and quality indicators.
Manually override automatic cover selection at any time.
Synopsis Chooser
View every available description from all metadata sources.
Compare language, source and quality score.
Select the preferred synopsis instead of relying solely on automatic scoring.

⚡ Other Improvements
Improved metadata merge accuracy across all providers.
Reduced unnecessary browser launches and duplicate fetch operations.
Better handling of multilingual libraries.
More reliable cover selection and metadata consistency.
Added independent per-book Update Cover option, allowing cover-only updates without modifying other metadata.