feat: text objects and motions for the pending buffer (#39)

* feat: text objects and motions for the pending buffer

Problem: the pending buffer has action-button mappings but no Vim
grammar. You cannot dat to delete a task, cit to change a description,
or ]] to jump to the next category header.

Solution: add textobj.lua with at/it (a task / inner task), aC/iC
(a category / inner category), ]]/[[ (next/prev header), and ]t/[t
(next/prev task). All text objects work in operator-pending and visual
modes; motions work in normal, visual, and operator-pending. Mappings
are configurable via the keymaps table and exposed as <Plug> mappings.

* fix(textobj): escape Lua pattern hyphen, fix test expectations

Problem: inner_task_range used unescaped '-' in Lua patterns, which
acts as a lazy quantifier instead of matching a literal hyphen. The
metadata-stripping logic also tokenized the full line including the
prefix, so the rebuilt string could never be found after the prefix.
All test column expectations were off by one.

Solution: escape hyphens with %-, rewrite metadata stripping to
tokenize only the description portion after the prefix, and correct
all test assertions to match actual rendered column positions.

* 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'.

* docs: text objects, motions, debug mode, queue view rename

Problem: vimdoc had no documentation for the new text objects, motions,
debug config, or the pending://queue buffer rename.

Solution: add text object and motion tables to the mappings section,
document all eight <Plug> mappings, add debug field to the config
reference, update config example with new keymap defaults, rename
priority view references to queue throughout the vimdoc.

* fix(textobj): use correct config variable, raise log level

Problem: motion keymaps (]], [[, ]t, [t) were never set because
`config.get().debug` referenced an undefined `config` variable,
crashing _setup_buf_mappings before the motion loop. Debug logging
also used vim.log.levels.DEBUG which is filtered by default.

Solution: replace `config` with `cfg` (already in scope) and raise
both debug notify calls from DEBUG to INFO.

* ci: formt

lua/pending/init.lua

@@ -88,6 +88,72 @@ function M._setup_buf_mappings(bufnr)
       vim.keymap.set('n', key --[[@as string]], fn, opts)
     end
   end
+
+  local textobj = require('pending.textobj')
+
+  ---@type table<string, { modes: string[], fn: fun(count: integer), visual_fn?: fun(count: integer) }>
+  local textobjs = {
+    a_task = {
+      modes = { 'o', 'x' },
+      fn = textobj.a_task,
+      visual_fn = textobj.a_task_visual,
+    },
+    i_task = {
+      modes = { 'o', 'x' },
+      fn = textobj.i_task,
+      visual_fn = textobj.i_task_visual,
+    },
+    a_category = {
+      modes = { 'o', 'x' },
+      fn = textobj.a_category,
+      visual_fn = textobj.a_category_visual,
+    },
+    i_category = {
+      modes = { 'o', 'x' },
+      fn = textobj.i_category,
+      visual_fn = textobj.i_category_visual,
+    },
+  }
+
+  for name, spec in pairs(textobjs) do
+    local key = km[name]
+    if key and key ~= false then
+      for _, mode in ipairs(spec.modes) do
+        if mode == 'x' and spec.visual_fn then
+          vim.keymap.set(mode, key --[[@as string]], function()
+            spec.visual_fn(vim.v.count1)
+          end, opts)
+        else
+          vim.keymap.set(mode, key --[[@as string]], function()
+            spec.fn(vim.v.count1)
+          end, opts)
+        end
+      end
+    end
+  end
+
+  ---@type table<string, fun(count: integer)>
+  local motions = {
+    next_header = textobj.next_header,
+    prev_header = textobj.prev_header,
+    next_task = textobj.next_task,
+    prev_task = textobj.prev_task,
+  }
+
+  for name, fn in pairs(motions) do
+    local key = km[name]
+    if cfg.debug then
+      vim.notify(
+        ('[pending] mapping motion %s → %s (buf=%d)'):format(name, key or 'nil', bufnr),
+        vim.log.levels.INFO
+      )
+    end
+    if key and key ~= false then
+      vim.keymap.set({ 'n', 'x', 'o' }, key --[[@as string]], function()
+        fn(vim.v.count1)
+      end, opts)
+    end
+  end
 end
 
 ---@param bufnr integer