feat(textobj): add debug mode, rename priority view buffer

Problem: the ]] motion reportedly lands one line past the header in
some environments, and ]t/[t may not override Neovim defaults. No
way to diagnose these at runtime. Also, pending://priority is a poor
buffer name for the flat ranked view.

Solution: add a debug config option (vim.g.pending = { debug = true })
that logs meta state, cursor positions, and mapping registration to
:messages at DEBUG level. Rename the buffer from pending://priority to
pending://queue. Internal view identifier stays 'priority'.

lua/pending/textobj.lua

@@ -4,6 +4,14 @@ local config = require('pending.config')
 ---@class pending.textobj
 local M = {}
 
+---@param ... any
+---@return nil
+local function dbg(...)
+  if config.get().debug then
+    vim.notify('[pending.textobj] ' .. string.format(...), vim.log.levels.DEBUG)
+  end
+end
+
 ---@param lnum integer
 ---@param meta pending.LineMeta[]
 ---@return string
@@ -264,17 +272,29 @@ function M.next_header(count)
   end
 
   local row = vim.api.nvim_win_get_cursor(0)[1]
+  dbg('next_header: cursor=%d, meta_len=%d, view=%s', row, #meta, view or 'nil')
   local found = 0
   count = math.max(1, count)
   for r = row + 1, #meta do
     if meta[r] and meta[r].type == 'header' then
       found = found + 1
+      dbg(
+        'next_header: found header at row=%d, cat=%s, found=%d/%d',
+        r,
+        meta[r].category or '?',
+        found,
+        count
+      )
       if found == count then
         vim.api.nvim_win_set_cursor(0, { r, 0 })
+        dbg('next_header: cursor set to row=%d, actual=%d', r, vim.api.nvim_win_get_cursor(0)[1])
         return
       end
+    else
+      dbg('next_header: row=%d type=%s', r, meta[r] and meta[r].type or 'nil')
     end
   end
+  dbg('next_header: no header found after row=%d', row)
 end
 
 ---@param count integer
@@ -290,11 +310,19 @@ function M.prev_header(count)
   end
 
   local row = vim.api.nvim_win_get_cursor(0)[1]
+  dbg('prev_header: cursor=%d, meta_len=%d', row, #meta)
   local found = 0
   count = math.max(1, count)
   for r = row - 1, 1, -1 do
     if meta[r] and meta[r].type == 'header' then
       found = found + 1
+      dbg(
+        'prev_header: found header at row=%d, cat=%s, found=%d/%d',
+        r,
+        meta[r].category or '?',
+        found,
+        count
+      )
       if found == count then
         vim.api.nvim_win_set_cursor(0, { r, 0 })
         return
@@ -312,17 +340,20 @@ function M.next_task(count)
   end
 
   local row = vim.api.nvim_win_get_cursor(0)[1]
+  dbg('next_task: cursor=%d, meta_len=%d', row, #meta)
   local found = 0
   count = math.max(1, count)
   for r = row + 1, #meta do
     if meta[r] and meta[r].type == 'task' then
       found = found + 1
       if found == count then
+        dbg('next_task: jumping to row=%d', r)
         vim.api.nvim_win_set_cursor(0, { r, 0 })
         return
       end
     end
   end
+  dbg('next_task: no task found after row=%d', row)
 end
 
 ---@param count integer
@@ -334,17 +365,20 @@ function M.prev_task(count)
   end
 
   local row = vim.api.nvim_win_get_cursor(0)[1]
+  dbg('prev_task: cursor=%d, meta_len=%d', row, #meta)
   local found = 0
   count = math.max(1, count)
   for r = row - 1, 1, -1 do
     if meta[r] and meta[r].type == 'task' then
       found = found + 1
       if found == count then
+        dbg('prev_task: jumping to row=%d', r)
         vim.api.nvim_win_set_cursor(0, { r, 0 })
         return
       end
     end
   end
+  dbg('prev_task: no task found before row=%d', row)
 end
 
 return M