feat(buffer): re-apply inline extmarks after edits

Problem: inline extmarks (checkbox overlays, strikethrough, header
highlights) were cleared during edits and only restored on `:w`,
leaving the buffer visually bare while editing.

Solution: extract `apply_inline_row()` from `apply_extmarks()` and
call it via `reapply_dirty_inline()` on `InsertLeave` and normal-mode
`TextChanged`. Insert-mode `TextChangedI` still only clears inline
marks on dirty rows to avoid overlay flicker while typing.

lua/pending/buffer.lua

@@ -116,6 +116,23 @@ function M.clear_dirty_rows()
   _dirty_rows = {}
 end
 
+---@param bufnr integer
+---@return nil
+function M.reapply_dirty_inline(bufnr)
+  if not next(_dirty_rows) then
+    return
+  end
+  local icons = config.get().icons
+  for row in pairs(_dirty_rows) do
+    local m = _meta[row]
+    if m then
+      vim.api.nvim_buf_clear_namespace(bufnr, ns_inline, row - 1, row)
+      apply_inline_row(bufnr, row - 1, m, icons)
+    end
+  end
+  _dirty_rows = {}
+end
+
 ---@param bufnr integer
 ---@return nil
 function M.attach_bytes(bufnr)
@@ -281,6 +298,55 @@ function M.get_fold()
   end
 end
 
+---@param bufnr integer
+---@param row integer
+---@param m pending.LineMeta
+---@param icons table
+local function apply_inline_row(bufnr, row, m, icons)
+  if m.type == 'filter' then
+    local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
+    vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
+      end_col = #line,
+      hl_group = 'PendingFilter',
+    })
+  elseif m.type == 'task' then
+    if m.status == 'done' then
+      local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
+      local col_start = line:find('/%d+/') and select(2, line:find('/%d+/')) or 0
+      vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, col_start, {
+        end_col = #line,
+        hl_group = 'PendingDone',
+      })
+    end
+    local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
+    local bracket_col = (line:find('%[') or 1) - 1
+    local icon, icon_hl
+    if m.status == 'done' then
+      icon, icon_hl = icons.done, 'PendingDone'
+    elseif m.priority and m.priority > 0 then
+      icon, icon_hl = icons.priority, 'PendingPriority'
+    else
+      icon, icon_hl = icons.pending, 'Normal'
+    end
+    vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, bracket_col, {
+      virt_text = { { '[' .. icon .. ']', icon_hl } },
+      virt_text_pos = 'overlay',
+      priority = 100,
+    })
+  elseif m.type == 'header' then
+    local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
+    vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
+      end_col = #line,
+      hl_group = 'PendingHeader',
+    })
+    vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
+      virt_text = { { icons.category .. ' ', 'PendingHeader' } },
+      virt_text_pos = 'overlay',
+      priority = 100,
+    })
+  end
+end
+
 ---@param bufnr integer
 ---@param line_meta pending.LineMeta[]
 local function apply_extmarks(bufnr, line_meta)
@@ -289,13 +355,7 @@ local function apply_extmarks(bufnr, line_meta)
   vim.api.nvim_buf_clear_namespace(bufnr, ns_inline, 0, -1)
   for i, m in ipairs(line_meta) do
     local row = i - 1
-    if m.type == 'filter' then
+    if m.type == 'task' then
-      local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
-      vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
-        end_col = #line,
-        hl_group = 'PendingFilter',
-      })
-    elseif m.type == 'task' then
       local due_hl = m.overdue and 'PendingOverdue' or 'PendingDue'
       local virt_parts = {}
       if m.show_category and m.category then
@@ -316,41 +376,8 @@ local function apply_extmarks(bufnr, line_meta)
           virt_text_pos = 'eol',
         })
       end
-      if m.status == 'done' then
-        local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
-        local col_start = line:find('/%d+/') and select(2, line:find('/%d+/')) or 0
-        vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, col_start, {
-          end_col = #line,
-          hl_group = 'PendingDone',
-        })
-      end
-      local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
-      local bracket_col = (line:find('%[') or 1) - 1
-      local icon, icon_hl
-      if m.status == 'done' then
-        icon, icon_hl = icons.done, 'PendingDone'
-      elseif m.priority and m.priority > 0 then
-        icon, icon_hl = icons.priority, 'PendingPriority'
-      else
-        icon, icon_hl = icons.pending, 'Normal'
-      end
-      vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, bracket_col, {
-        virt_text = { { '[' .. icon .. ']', icon_hl } },
-        virt_text_pos = 'overlay',
-        priority = 100,
-      })
-    elseif m.type == 'header' then
-      local line = vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false)[1] or ''
-      vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
-        end_col = #line,
-        hl_group = 'PendingHeader',
-      })
-      vim.api.nvim_buf_set_extmark(bufnr, ns_inline, row, 0, {
-        virt_text = { { icons.category .. ' ', 'PendingHeader' } },
-        virt_text_pos = 'overlay',
-        priority = 100,
-      })
     end
+    apply_inline_row(bufnr, row, m, icons)
   end
 end
 

lua/pending/init.lua

@@ -251,7 +251,7 @@ function M._setup_autocmds(bufnr)
       end
     end,
   })
-  vim.api.nvim_create_autocmd({ 'TextChanged', 'TextChangedI' }, {
+  vim.api.nvim_create_autocmd('TextChangedI', {
     group = group,
     buffer = bufnr,
     callback = function()
@@ -263,6 +263,25 @@ function M._setup_autocmds(bufnr)
       end
     end,
   })
+  vim.api.nvim_create_autocmd('TextChanged', {
+    group = group,
+    buffer = bufnr,
+    callback = function()
+      if not vim.bo[bufnr].modified then
+        return
+      end
+      buffer.reapply_dirty_inline(bufnr)
+    end,
+  })
+  vim.api.nvim_create_autocmd('InsertLeave', {
+    group = group,
+    buffer = bufnr,
+    callback = function()
+      if vim.bo[bufnr].modified then
+        buffer.reapply_dirty_inline(bufnr)
+      end
+    end,
+  })
   vim.api.nvim_create_autocmd('WinClosed', {
     group = group,
     callback = function(ev)