Problem: Highlight inspection is limited to a single position, and its
result types do not document the fields shared by different highlight
sources.

Solution: Accept end_row/end_col in vim.inspect_pos to inspect a range.
Keep range ends exclusive and retain the existing single-position
behavior.

Support Ex line ranges in :Inspect, including Visual selections.
Document named result types, expose shared highlight fields, and keep
the existing extmark details and buffer field for compatibility.

AI-assisted

fix(lua): enable param-type-mismatch diagnostic

Problem: get_captures_at_pos() only returns captures at one position. It
cannot query a whole line or range. It can also miss captures from
injected languages outside the visible area.

Solution: Add vim.treesitter.get_captures() with a required start and an
optional exclusive stop. Accept row numbers or {row, col} positions.
Without a stop, query one position or a whole line. Parse the requested
range and return capture coordinates.

Deprecate get_captures_at_pos() with a compatibility wrapper and migrate
its internal callers. Keep get_captures_at_cursor() for capture names at
a window's cursor.

AI-assisted

Problem: Argument type mismatches are excluded from EmmyLua checks.

Solution: Correct runtime annotations and calls, document local checker
workarounds, and enable the diagnostic.

AI-assisted

Enable checks for unused code, deprecated calls, return types, and
annotations.

Fix the warnings and replace the deprecated highlight function. Keep
exceptions where old APIs are still needed or the checker gets it wrong.

AI-assisted

The new lua based runner replaces Makefile, runnvim.sh and runnvim.vim

As it happens, we run a `--headless` nvim inside a `:terminal` layer,
this is pointless.
Also there is still a lot remnants for oldesttests, but we don't
have any except for test1.in which just checks the environment
for following, nonexistant oldesttests. so just skip that.

For now, the actual vimscript code which runs in vim-under-test is
completely unchanged.

On macos, luajit is finally working with the latest ziglua master.
Also fix some minor bugs regarding locales, such as incorrect
HAVE_WORKING_LIBINTL checks