[starx710]

Windows UNC patterns such as r"\\*.custom*\*" can panic in glob_with before iteration: the reconstructed path adds an implicit root separator, so the computed root length is 14 bytes while the original pattern is only 13 bytes.

Compute the root length from the original prefix component and count a root separator only when it is present in the input. This keeps both slices in the original string and removes the normalized-path allocations. UNC server/share wildcard enumeration and the existing unsupported verbatim UNC behavior are unchanged.

Add Windows regressions for the reported pattern, Unicode UNC prefixes, forward slashes, trailing and repeated separators, and unsupported verbatim UNC prefixes. Extend the filesystem integration test with Unicode filenames and drive-rooted, repeated-separator, current-drive-rooted, and verbatim disk patterns.

Fixes #134.

Validation on native Windows (x86_64-pc-windows-gnu):

• cargo test --all with RUSTFLAGS=-Dwarnings and RUSTDOCFLAGS=-Dwarnings: 19 unit, 1 integration, and 5 doc tests passed; 2 existing doc examples ignored.
• The new UNC regression fails with the original out-of-bounds panic against unchanged upstream production code and passes with this fix. A separate path-dependency reproducer also passes all 5 cases.
• cargo fmt -- --check and git diff --check passed.
• Rust 1.63 compiled the actual library source with rustc --edition=2021 --crate-type lib -D warnings; test dependencies were excluded.
• Linux-target library Clippy passed with warnings denied: cargo clippy --all --target x86_64-unknown-linux-gnu -- -Aclippy::while_let_loop. This was a cross-target static check; Linux/macOS runtime tests await CI.
• Windows all-targets Clippy passed with command-line allowances for existing upstream lints (match_like_matches_macro, to_string_in_format_args, bind_instead_of_map, and iter_skip_next), in addition to the upstream while_let_loop allowance. No source lint allowances were added.

Implementation and tests were prepared with assistance from OpenAI Codex. The validation above was executed locally.