feat(api): add '/review' command for code review

lua/opencode/api.lua

@@ -941,6 +941,39 @@ function M.toggle_reasoning_output()
   ui.render_output()
 end
 
+---@type fun(): Promise<void>
+M.review = Promise.async(function(args)
+  local id = require('opencode.id')
+
+  local new_session = core.create_new_session('Code review checklist for diffs and PRs'):await()
+  if not new_session then
+    vim.notify('Failed to create new session', vim.log.levels.ERROR)
+    return
+  end
+  if not core.initialize_current_model():await() or not state.current_model then
+    vim.notify('No model selected', vim.log.levels.ERROR)
+    return
+  end
+  local providerId, modelId = state.current_model:match('^(.-)/(.+)$')
+  if not providerId or not modelId then
+    vim.notify('Invalid model format: ' .. tostring(state.current_model), vim.log.levels.ERROR)
+    return
+  end
+  state.active_session = new_session
+  M.open_input():await()
+  state.api_client
+    :send_command(state.active_session.id, {
+      command = 'review',
+      arguments = table.concat(args or {}, ' '),
+      model = state.current_model,
+    })
+    :and_then(function()
+      vim.schedule(function()
+        require('opencode.history').write('/review ' .. table.concat(args or {}, ' '))
+      end)
+    end)
+end)
+
 ---@type table<string, OpencodeUICommand>
 M.commands = {
   open = {
@@ -1008,6 +1041,14 @@ M.commands = {
     fn = M.swap_position,
   },
 
+  review = {
+    desc = 'Review changes [commit|branch|pr], defaults to uncommitted changes',
+    fn = function(args)
+      M.review(args)
+    end,
+    nargs = '+',
+  },
+
   session = {
     desc = 'Manage sessions (new/select/child/compact/share/unshare/rename)',
     completions = { 'new', 'select', 'child', 'compact', 'share', 'unshare', 'agents_init', 'rename' },
@@ -1304,6 +1345,11 @@ M.slash_commands_map = {
   ['/rename'] = { fn = M.rename_session, desc = 'Rename current session' },
   ['/thinking'] = { fn = M.toggle_reasoning_output, desc = 'Toggle reasoning output' },
   ['/reasoning'] = { fn = M.toggle_reasoning_output, desc = 'Toggle reasoning output' },
+  ['/review'] = {
+    fn = M.review,
+    desc = 'Review changes [commit|branch|pr], defaults to uncommitted changes',
+    args = true,
+  },
 }
 
 M.legacy_command_map = {
@@ -1442,6 +1488,7 @@ M.get_slash_commands = Promise.async(function()
       slash_cmd = slash_cmd,
       desc = def.desc,
       fn = def.fn,
+      args = def.args or false,
     })
   end