feat(shell): enable PTY by default and various enhancements

### Shell & Interactive Terminal Improvements
- PTY shell is now enabled by default instead of disabled
- Improved shell output rendering, process termination, and added fallback warning
- Background commands now properly capture subprocess PIDs on non-Windows

### Coding Plan Improvements
- Simplified auth message, added /model tip, improved system info display
- Reordered model list to prioritize glm-5, kimi-k2.5, MiniMax-M2.5
- Model selection is now preserved when updating if the model still exists

### Other Changes
- Added shared symlink utility; debug logs now have latest alias
- Unknown settings warnings go to debug log instead of user-facing warnings
- Fixed subagent confirmation state detection
- Removed debug UI from AgentCreationWizard

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

packages/cli/src/ui/auth/useAuth.ts

@@ -389,13 +389,24 @@ export const useAuthCommand = (
           {
             type: MessageType.INFO,
             text: t(
-              'Authenticated successfully with {{region}}. API key and model configs saved to settings.json (backed up).',
+              'Authenticated successfully with {{region}}. API key and model configs saved to settings.json.',
               { region: t('Alibaba Cloud Coding Plan') },
             ),
           },
           Date.now(),
         );
 
+        // Hint about /model command
+        addItem(
+          {
+            type: MessageType.INFO,
+            text: t(
+              'Tip: Use /model to switch between available Coding Plan models.',
+            ),
+          },
+          Date.now(),
+        );
+
         // Log success
         const authEvent = new AuthEvent(
           AuthType.USE_OPENAI,