Add optional Git blame annotations for working-tree files

[Matei02355]

Show commit attribution before line numbers with --blame or the blame style component. Keep it opt-in, including when using the full style, and expose the same controls through PrettyPrinter.

Use gix's blame support to follow renames and merge history, then map HEAD attribution onto the current worktree with Git's clean-filter pipeline. Insertions, modifications and staged changes are marked uncommitted; unchanged lines retain their original commits. Handle linked worktrees, unborn repositories, untracked files and CRLF conversion. Preserve physical attribution when ranges, squeezing or nonblank numbering change the displayed line numbers.

Add --blame-format for commit hashes, author/committer names, emails, dates, Unix times and subjects. Sanitize metadata, truncate by Unicode grapheme boundaries to a bounded sidebar width, and leave wrapped continuation annotations empty. Ordinary UTF-8 files are supported; stdin, preprocessing, unbuffered input, binary files and files outside repositories omit attribution. History is computed before printing, so large histories can delay initial output.

This revisits the static blame feature proposed by @userwiths in #2851, which was welcomed after a rebase and later closed as stale. The implementation uses the repository's current gix dependency, enabling its blame feature and adding gix-blame 0.16.0.

Validation: all 487 all-feature tests passed (7 ignored), including 14 regressions comparing attribution against git blame across edits, renames, merges, worktrees and CRLF conversion. All 8 default-feature help tests passed. All-target/all-feature Clippy with warnings denied, formatting, whitespace checks, Bash/Zsh completion syntax, and a library build without Git or paging passed. README, manual, help snapshots and all four completions are updated. GitHub CI will validate other platforms.

Fixes #1536. Fixes #2810.