🐛 BUG: Improve logging for how to resolve conflict in configuration files

### Which Cloudflare product(s) does this pertain to?

Wrangler

### What versions are you using?

4.6.0 [Wrangler]

### What operating system and version are you using?

Mac Sonoma

### Please provide a link to a minimal reproduction

_No response_

### Describe the Bug

The error message for conflicting configurations does not provide any guidance on how to solve (errors should explain why they are occurring and give guidance on how to fix).


### Please provide any relevant error logs

_No response_

Start by reproducing the conflicting-configuration error in Wrangler 4.6.0 on macOS, then trace where the message is generated. Improve the error so it explains why the configurations conflict and gives concrete guidance for resolving them; verify the updated output against the reported scenario.

Written by the indexing model from the issue text.