[CoreyKaylor]

Closes #10. This adds pixel-resolution minimaps beside each diff pane, plus an opt-in minimap for ordinary editor windows. It's opened early to gather feedback: please try it and comment, especially on the questions at the bottom.

What it does

Diff view overview strips

• In terminals with Kitty graphics and Unicode placeholders (Ghostty, Kitty, …) each strip is an image. Every other terminal (tmux, iTerm2, Terminal.app) keeps the existing one-column cell gutter.
• The code shape (default on): the file drawn as tiny syntax-coloured runs, so you can see where you are by the shape of the code. Colours come from treesitter captures, falling back to legacy syntax and then Normal.
• Hunk marks are drawn at pixel resolution and the current chunk is outlined.
• Overlays:
  • the viewport band (always visible);
  • 'hlsearch' matches;
  • the visual selection;
  • diagnostics.
• Scale: fills the window height, with a min_reduction floor so short files aren't stretched.
• Mouse: click or drag to jump; the wheel scrolls the pane. No mappings are added to your buffers.
• Focus-follow: the focused pane's strip is full width (12 cells), the other a squeezed 4-cell version of the same shape. They swap when focus moves, and the panes keep equal widths.
• Cost: the image is re-sent only when hunks, size or palette change. Scrolling and cursor moves only swap highlights.

Editor windows: :DiffBanditMinimap [toggle|open|close], or minimap.auto = true

• A float on the window's right edge showing git hunks against the index, diagnostics, search, selection and the viewport.
• Hidden on narrow windows. Skips help, quickfix and the like, and DiffBandit's own tabs.

Config

require("diffbandit").setup({
  ui = {
    overview = {
      renderer = "auto",   -- "cells" to opt out of images
      code_shape = true,
      code_width = 12,
      focus_follow = true,
      compact_width = 4,
      min_reduction = nil, -- auto
      -- viewport / search / selection / mouse toggles
    },
  },
  minimap = {
    auto = false,          -- editor-window minimaps
    git = true,
    diagnostics = { enabled = true, min_severity = "warn" },
    min_window_width = 60,
  },
})

Internals

• minimap/ is a shared Minimap component (target window + provider + placement). The diff view's strips are managed minimaps in the layout's sidecar splits; editor minimaps are floats.
• The diff view's minimaps borrow the session's renderer, so strip width and paint always agree after a probe or a fallback.
• The old session/overview.lua is gone.
• Tests: tests/specs/45_kitty.lua (raster, images, overlays, code shape, mouse, focus-follow) and the new tests/specs/55_minimap.lua (editor minimap). The full suite passes.

Feedback wanted

1. Code shape on by default: is it useful, or noisy? Is 12 cells the right default width?
2. Focus-follow: does the wide/compact swap feel natural, or is the pane shift on focus distracting? Should compact_width be smaller or larger?
3. Editor minimap: would you use it? Is a float on the right edge the right placement, or would you prefer a split?
4. Overlays: are search, selection and diagnostics all worth showing, or is it too busy?
5. Terminals: any rendering problems in your terminal (colour, blur, misplaced placeholders)? Please mention the terminal and font size.
6. Merge view: this PR leaves the merge view as it was. Do you want minimaps there too?

[CoreyKaylor]

Closing in favor of extracting the capability into its own plugin.
https://github.com/CoreyKaylor/purrview.nvim