fix: revert .golangci.yml to main, fix all lint issues in code

- Restore original .golangci.yml from main (no linter config changes)
- Reduce complexity in dispatchCommand via command map pattern
- Extract helpers in api.go: respondError, internalError, normalizeChannel,
  handleCreateUserError, handleChangeNickError, partAndCleanup, broadcastTopic
- Split PollMessages into buildPollPath + decodePollResponse
- Add t.Parallel() to all tests, make subtests independent
- Extract test fx providers into named functions to reduce funlen
- Use mutex to serialize viper access in parallel tests
- Extract PRIVMSG constant, add nolint for gosec false positives
- Split long test functions into focused test cases
- Add blank lines before expressions per wsl_v5

cmd/chat-cli/ui.go

@@ -80,6 +80,7 @@ func (ui *UI) AddLine(bufferName, line string) {
 		cur := ui.buffers[ui.currentBuffer]
 		if cur != buf {
 			buf.Unread++
+
 			ui.refreshStatusBar()
 		}