feat(forge): add gx keymap to open forge links in browser

Problem: Forge shorthand tokens like `gh:user/repo#42` are concealed in
the buffer so Neovim's built-in `gx` cannot recognize them as URLs.
Full URLs are also concealed, making `gx` unreliable.

Solution: Add `open_link` action (default `gx`) that reads `forge_spans`
from line metadata. If the cursor is on a forge token, that link opens;
otherwise the last ref on the line is used. Delegates to `vim.ui.open()`.

doc/pending.txt

@@ -349,6 +349,7 @@ Default buffer-local keys: ~
     `gb`          Toggle blocked status (`blocked`)
     `g/`          Toggle cancelled status (`cancelled`)
     `ge`          Open markdown detail buffer for task notes (`edit_notes`)
+    `gx`          Open the forge link under the cursor in a browser (`open_link`)
     `gf`          Prompt for filter predicates (`filter`)
     `<Tab>`       Switch between category / queue view (`view`)
     `gz`          Undo the last `:w` save (`undo`)
@@ -494,6 +495,13 @@ old keys to `false`: >lua
     Shows a read-only metadata header and editable notes below a `---`
     separator. Press `q` to return to the task list. Default key: `ge`.
 
+                                                *<Plug>(pending-open-link)*
+<Plug>(pending-open-link)
+    Open the forge link under the cursor in a browser via |vim.ui.open()|.
+    If the cursor is positioned on a forge token (`gh:user/repo#42` or a
+    full URL), that link is opened. Otherwise, the last forge reference on
+    the line is used. No-op on lines without forge links. Default key: `gx`.
+
                                                    *<Plug>(pending-open-line)*
 <Plug>(pending-open-line)
     Insert a correctly-formatted blank task line below the cursor.

lua/pending/config.lua

@@ -83,6 +83,7 @@
 ---@field priority_down_visual? string|false
 ---@field cancelled? string|false
 ---@field edit_notes? string|false
+---@field open_link? string|false
 
 ---@class pending.CategoryViewConfig
 ---@field order? string[]
@@ -165,6 +166,7 @@ local defaults = {
     blocked = 'gb',
     cancelled = 'g/',
     edit_notes = 'ge',
+    open_link = 'gx',
     priority_up = '<C-a>',
     priority_down = '<C-x>',
     priority_up_visual = 'g<C-a>',

lua/pending/init.lua

@@ -404,6 +404,9 @@ function M._setup_buf_mappings(bufnr)
     edit_notes = function()
       M.open_detail()
     end,
+    open_link = function()
+      M.open_link()
+    end,
   }
 
   for name, fn in pairs(actions) do
@@ -931,6 +934,31 @@ function M.open_detail()
   end, { buffer = detail_bufnr })
 end
 
+---@return nil
+function M.open_link()
+  local bufnr = buffer.bufnr()
+  if not bufnr then
+    return
+  end
+  local row = vim.api.nvim_win_get_cursor(0)[1]
+  local meta = buffer.meta()
+  if not meta[row] or meta[row].type ~= 'task' then
+    return
+  end
+  local spans = meta[row].forge_spans
+  if not spans or #spans == 0 then
+    return
+  end
+  local col = vim.api.nvim_win_get_cursor(0)[2]
+  for _, span in ipairs(spans) do
+    if col >= span.col_start and col < span.col_end then
+      vim.ui.open(span.ref.url)
+      return
+    end
+  end
+  vim.ui.open(spans[#spans].ref.url)
+end
+
 ---@param direction 'up'|'down'
 ---@return nil
 function M.move_task(direction)

plugin/pending.lua

@@ -411,6 +411,10 @@ vim.keymap.set('n', '<Plug>(pending-edit-notes)', function()
   require('pending').open_detail()
 end)
 
+vim.keymap.set('n', '<Plug>(pending-open-link)', function()
+  require('pending').open_link()
+end)
+
 vim.keymap.set('n', '<Plug>(pending-priority-up)', function()
   require('pending').increment_priority()
 end)