refactor(nvim): single source of truth for per-ft formatting width

- vim.g.dotfiles.textwidth = { sh=80, lua=120, markdown=120, gitcommit=72 }
  defined once in init.lua.
- bash/lua/markdown/gitcommit ftplugins + render-markdown read from it;
  mdformat --wrap already follows vim.bo.textwidth.
- gitcommit gets an explicit textwidth line (was implicit runtime 72).
- Behavior unchanged; one number now propagates everywhere.

6 files changed, 11 insertions, 5 deletions

diff --git a/after/ftplugin/bash.lua b/after/ftplugin/bash.lua
index d46657d..6e10433 100644
--- a/after/ftplugin/bash.lua
+++ b/after/ftplugin/bash.lua
@@ -1,4 +1,4 @@
-vim.opt_local.textwidth = 80 -- gw wraps at this value
+vim.opt_local.textwidth = vim.g.dotfiles.textwidth.sh -- gw wraps at this value
 vim.opt_local.colorcolumn = "+1" -- Highlight one column after 'textwidth'
 vim.opt_local.complete = {
 	"o", -- 'omnifunc'
diff --git a/after/ftplugin/gitcommit.lua b/after/ftplugin/gitcommit.lua
index fea0559..26cac51 100644
--- a/after/ftplugin/gitcommit.lua
+++ b/after/ftplugin/gitcommit.lua
@@ -1,3 +1,4 @@
+vim.opt_local.textwidth = vim.g.dotfiles.textwidth.gitcommit -- gw wraps at this value
 vim.opt_local.colorcolumn = "+1" -- Highlight one column after 'textwidth'
 vim.opt_local.tabstop = 2 -- CommonMark expects two spaces for indentation
 vim.opt_local.shiftwidth = 0
diff --git a/after/ftplugin/lua.lua b/after/ftplugin/lua.lua
index 756026e..05e4978 100644
--- a/after/ftplugin/lua.lua
+++ b/after/ftplugin/lua.lua
@@ -24,7 +24,7 @@ local function format()
 	vim.fn.winrestview(view)
 end
 
-vim.opt_local.textwidth = 120 -- gw wraps at this value
+vim.opt_local.textwidth = vim.g.dotfiles.textwidth.lua -- gw wraps at this value
 vim.opt_local.colorcolumn = "+1" -- Highlight one column after 'textwidth'
 vim.opt_local.complete = {
 	"o", -- 'omnifunc'
diff --git a/after/ftplugin/markdown.lua b/after/ftplugin/markdown.lua
index c7be170..c18397e 100644
--- a/after/ftplugin/markdown.lua
+++ b/after/ftplugin/markdown.lua
@@ -57,7 +57,7 @@ vim.opt_local.relativenumber = false
 vim.opt_local.signcolumn = "auto"
 vim.opt_local.foldcolumn = "0"
 --
-vim.opt_local.textwidth = 120 -- gw wraps at this value
+vim.opt_local.textwidth = vim.g.dotfiles.textwidth.markdown -- gw wraps at this value
 vim.opt_local.foldlevel = 1
 -- Replace concealed text with a character from `'listchars'`
 -- With `'foldmethod'` set to `expr` and `'foldlevel'` set to 2 fenced code blocks are concealed and completely invisible
diff --git a/init.lua b/init.lua
index e78cb27..a7a33e3 100644
--- a/init.lua
+++ b/init.lua
@@ -2,7 +2,12 @@ if vim.env.DOTFILES_DIR == nil then
 	vim.notify("DOTFILES_DIR is not set!", vim.log.levels.WARN)
 end
 
-vim.g.dotfiles = { augroup = vim.api.nvim_create_augroup("dotfiles", {}) }
+vim.g.dotfiles = {
+	augroup = vim.api.nvim_create_augroup("dotfiles", {}),
+	-- Single source of truth for per-filetype formatting width
+	-- (textwidth → gw, mdformat --wrap, render-markdown block widths).
+	textwidth = { sh = 80, lua = 120, markdown = 120, gitcommit = 72 },
+}
 
 ------------------------------------------------------------------------------------------------------------------------
 -- Local functions
diff --git a/plugin/50-markdown.lua b/plugin/50-markdown.lua
index 9642617..87a7838 100644
--- a/plugin/50-markdown.lua
+++ b/plugin/50-markdown.lua
@@ -17,7 +17,7 @@ require("nvim-treesitter").install({
 	"yaml",
 })
 
-local markdown_textwidth = 120
+local markdown_textwidth = vim.g.dotfiles.textwidth.markdown
 require("render-markdown").setup({
 	heading = { width = "block", min_width = markdown_textwidth },
 	code = { position = "center", sign = false, width = "block", min_width = markdown_textwidth / 2, left_margin = 2 },