fix(subagents): change limits from hard errors to soft warnings

- Increase description warning threshold from 500 to 1,000 characters
- Change system prompt 10,000 char limit from error to warning
- Remove intermediate 5,000 char warning threshold for system prompts
- Update documentation to reflect soft warning behavior

This provides more flexibility for users while still guiding them
toward better practices.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

packages/cli/src/ui/components/subagents/create/CreationSummary.tsx

@@ -94,7 +94,7 @@ export function CreationSummary({
       }
 
       // Check length warnings
-      if (state.generatedDescription.length > 300) {
+      if (state.generatedDescription.length > 1000) {
         allWarnings.push(
           t('Description is over {{length}} characters', {
             length: state.generatedDescription.length.toString(),