fix(treesitter): stop treesitter for markdown to fix nvim 0.12 injection crash

nvim 0.12 changed _apply_directives to pass TSNode[] instead of TSNode
for captures. nvim-treesitter's set-lang-from-info-string! predicate calls
node:range() on the array, crashing both the highlighter and vim-matchup.

Stop treesitter for markdown via FileType autocmd and disable matchup's
treesitter engine for markdown via vim.g.matchup_treesitter_disabled.
Revert the ineffective nvim-treesitter module-level disable that was
added in the previous commit.

Author: Venkata Subramani Renduchintala

lua/autocmds.lua

@@ -34,6 +34,17 @@ vim.filetype.add({
 	},
 })
 
+-- nvim-treesitter is incompatible with nvim 0.12's captures API for markdown
+-- injections (TSNode[] vs TSNode mismatch in set-lang-from-info-string!),
+-- causing crashes in both the highlighter and vim-matchup. Stop treesitter
+-- for markdown until upstream fixes the predicate handler.
+vim.api.nvim_create_autocmd("FileType", {
+	pattern = "markdown",
+	callback = function()
+		vim.treesitter.stop()
+	end,
+})
+
 -- Disable automatic line breaks
 vim.api.nvim_create_autocmd("FileType", {
   pattern = "*",

lua/plugins/configs/matchup.lua

@@ -2,5 +2,7 @@ return {
   "andymass/vim-matchup",
   config = function()
     vim.g.matchup_matchparen_offscreen = { method = "popup" }
+    -- disable matchup's treesitter engine for markdown (same nvim 0.12 incompatibility)
+    vim.g.matchup_treesitter_disabled = { "markdown" }
   end,
 }

lua/plugins/configs/treesitter.lua

@@ -117,9 +117,6 @@ return {
 				-- enables vim-matchup integration
 				enable = true,
 				enable_quotes = true,
-				-- markdown injections (bash/sh code blocks) trigger a nil-node crash
-				-- in the treesitter injection layer; fall back to regex matching there
-				disable = { "markdown" },
 			},
 			-- incremental_selection = {
 			--     enable = true,