fix(utils): handle 1xx HTTP status codes in curl utils (#1540)

Update the curl utility to treat 1xx (informational) HTTP status codes,
such as 100 (Continue), as non-errors in both GET and POST requests.
Previously, only 2xx (success) codes were considered valid, which could
cause issues with streaming or intermediate responses. This change
improves compatibility with APIs that use informational status codes.

Closes #1508

Author: deathbeam

lua/CopilotChat/utils/curl.lua

@@ -48,7 +48,10 @@ M.get = async.wrap(function(url, opts, callback)
 
   args.callback = function(response)
     log.debug('GET response:', response)
-    if response and not vim.startswith(tostring(response.status), '20') then
+    -- HTTP status codes: 1xx (informational), 2xx (success)
+    -- Status 100 (Continue) is common with streaming responses
+    local status_str = tostring(response.status)
+    if response and not vim.startswith(status_str, '1') and not vim.startswith(status_str, '20') then
       callback(response, response.body)
       return
     end
@@ -96,7 +99,10 @@ M.post = async.wrap(function(url, opts, callback)
         log.debug('Failed to remove temp file:', temp_file_path, err)
       end
     end
-    if response and not vim.startswith(tostring(response.status), '20') then
+    -- HTTP status codes: 1xx (informational), 2xx (success)
+    -- Status 100 (Continue) is common with streaming responses
+    local status_str = tostring(response.status)
+    if response and not vim.startswith(status_str, '1') and not vim.startswith(status_str, '20') then
       callback(response, response.body)
       return
     end