'default' inherits algorithm and linematch from diffopt, 'vscode' uses
the FFI library. Removes the need for diffs.nvim to duplicate settings
that users already control globally.
line_hl_group bg occupies a separate rendering channel from hl_group in
Neovim's extmark system, causing character-level bg-only highlights to be
invisible regardless of priority. Switching to hl_group + hl_eol ensures
all backgrounds compete in the same channel.
Also reorders priorities (Normal 198 < line bg 199 < syntax 200 < char
bg 201), bumps char-level blend alpha from 0.4 to 0.7 for visibility,
and adds debug logging throughout the intra pipeline.
The previous 70% alpha blend of DiffAdd bg was nearly identical to the
40% line-level blend, making char-level highlights invisible. Now blends
the bright diffAdded/diffRemoved foreground color (same base as line
number fg) into the char-level bg, matching GitHub/VSCode intensity.
Also bumps intra.max_lines default from 200 to 500.
Line-level backgrounds (DiffsAdd/DiffsDelete) now get a second tier:
changed characters within modified lines receive an intense background
overlay (DiffsAddText/DiffsDeleteText at 70% alpha vs 40% for lines).
Treesitter foreground colors show through since the extmarks only set bg.
diff.lua extracts contiguous -/+ change groups from hunk lines and diffs
each group byte-by-byte using vim.diff(). An optional libvscodediff FFI
backend (lib.lua) auto-downloads the .so from codediff.nvim releases and
falls back to native if unavailable.
New config: highlights.intra.{enabled, algorithm, max_lines}. Gated by
max_lines (default 200) to avoid stalling on huge hunks. Priority 201
sits above treesitter (200) so the character bg always wins.
Closes#60
Adds du/dU keymaps to fugitive's :Git status buffer for opening unified
diffs instead of side-by-side diffs:
- du opens horizontal split (mirrors dd)
- dU opens vertical split (mirrors dv)
Parses status buffer lines to extract filename and detect section
(staged/unstaged/untracked). For staged files, diffs index vs HEAD.
For unstaged files, diffs working tree vs index.
Configurable via vim.g.diffs.fugitive.horizontal/vertical (set to
false to disable).
