261020.8 · 1d9084be82cefff23a06b2d091d4d484f78cdb3f

test: make the suite pass consistently on Windows/slow machines

- screenshot captures now retry (Linux: 4x250ms, else 20x500ms) with
a fresh capture per attempt (nested process spawns like the
`line_query` transform can take >10s before the preview renders)
- wait until the screen stops changing before capturing
- invalidate the whole screen before capturing on Windows: moving
floats (fzf term float, preview scrollbar thumb) leave previously
composited cells behind which plain `:redraw` skips as valid
- `child.stop` uses rpcnotify + jobwait/jobstop instead of rpcrequest
`0cquit`, which could hang indefinitely on Windows
- headless test children default to `pipe_cmd` on Windows
- skip the `find` executable case on Windows: `dir /s/b` output cannot
reproduce the Linux `find` reference (absolute paths, attribute and
symlink count differences)
- ui_select #2743 test: hermetic `$TMUX` (inherit + real fzf popup
fails in the headless child) and `vim.NIL` result comparison

@@ -138,6 +138,11 @@ T["files"]["executable"] = new_set({ parametrize = { { "fd" }, { "rg" }, { "find       exclude = [[{ "fd", "fdfind" }]]       opts = { rg_opts = '--files -g "!.git" --sort=path -g !tests/**' }     else+      -- `dir /s/b` emits absolute paths (`<cwd>\file`), the cwd here is+      -- `deps/fzf-lua` so the `findstr` filters can't reproduce the relative+      -- `find` listing of the Linux reference (attribute and symlink+      -- differences change the entry count as well)+      helpers.SKIP_IF_WIN("`dir` output cannot match the linux `find` reference")       exclude = [[{ "fd", "fdfind", "rg" }]]       opts = {         find_opts =