fix(ci): unused vars

lua/cp/async/jobs.lua

@@ -27,7 +27,7 @@ function M.kill_job(job_id)
 end
 
 function M.kill_all_jobs()
-  for job_id, job in pairs(current_jobs) do
+  for _, job in pairs(current_jobs) do
     job:kill(9)
   end
   current_jobs = {}

lua/cp/async/setup.lua

@@ -149,7 +149,7 @@ function M.setup_problem_async(contest_id, problem_id, language)
   async.finish_contest_operation()
 end
 
-function M.start_background_problem_scraping(contest_id, problems, config)
+function M.start_background_problem_scraping(contest_id, problems, _)
   cache.load()
   local platform = state.get_platform() or ''
   local missing_problems = {}

spec/async_integration_spec.lua

@@ -140,7 +140,7 @@ describe('async integration', function()
     it('handles complete contest setup workflow', function()
       local setup_completed = false
       local mock_async_setup = {
-        setup_contest_async = function(contest_id, _)
+        setup_contest_async = function(contest_id)
           assert.equals('abc123', contest_id)
           setup_completed = true
         end,

spec/async_scraper_spec.lua

@@ -26,7 +26,7 @@ describe('cp.async.scraper', function()
       end,
     }
 
-    vim.system = function(cmd, opts, callback)
+    vim.system = function(cmd, _, callback)
       local result = { code = 0, stdout = '{}', stderr = '' }
       if cmd[1] == 'ping' then
         result = { code = 0 }
@@ -77,7 +77,7 @@ describe('cp.async.scraper', function()
     end)
 
     it('calls callback with error on network failure', function()
-      vim.system = function(cmd, opts, callback)
+      vim.system = function(cmd, _, callback)
         if cmd[1] == 'ping' then
           callback({ code = 1 })
         end
@@ -107,7 +107,7 @@ describe('cp.async.scraper', function()
     end)
 
     it('calls callback with error on subprocess failure', function()
-      vim.system = function(cmd, opts, callback)
+      vim.system = function(cmd, _, callback)
         if cmd[1] == 'ping' then
           callback({ code = 0 })
         else
@@ -125,7 +125,7 @@ describe('cp.async.scraper', function()
     end)
 
     it('calls callback with error on invalid JSON', function()
-      vim.system = function(cmd, opts, callback)
+      vim.system = function(cmd, _, callback)
         if cmd[1] == 'ping' then
           callback({ code = 0 })
         else
@@ -156,7 +156,7 @@ describe('cp.async.scraper', function()
     end)
 
     it('handles network failure gracefully', function()
-      vim.system = function(cmd, opts, callback)
+      vim.system = function(cmd, _, callback)
         if cmd[1] == 'ping' then
           callback({ code = 1 })
         end

spec/async_setup_spec.lua

@@ -11,7 +11,7 @@ describe('cp.async.setup', function()
     }
 
     mock_scraper = {
-      scrape_contest_metadata_async = function(platform, contest_id, callback)
+      scrape_contest_metadata_async = function(_, _, callback)
         callback({
           success = true,
           problems = {