[Bedrock] Add max output token probe settings control

[edelauna]

Which API Provider are you using?

AWS Bedrock

Which Model are you using?

Selected Bedrock model/profile target

What happened?

Bedrock settings need a UI control for running the max-output-token probe, displaying its state, and saving or clearing the scoped override.

Steps to reproduce

1. Review the max output token probe UI proposed in [ENHANCEMENT] Improve Amazon Bedrock support #125.
2. Add detect, probing, success, error, override-active, and reset states.
3. Wire updates through local SettingsView cached state.

Relevant API REQUEST output

N/A

Additional context

Parent issue: #124
Source PR: #125
Story point estimate: 1

Suggested PR group: PR 3 - discovery/settings UI

Acceptance criteria:

• Clicking detect sends a probe request for the resolved Bedrock target.
• Successful probe updates the local cached provider settings.
• Reset clears both the override and target ID.
• Override status is only shown for the matching target.
• Webview tests cover the UI state transitions.