fix(ai-proxy): map adaptive effort to sibling output_config in Bedrock

[srpatcha]

Ⅰ. Describe what this PR does

Fixes #4170

When ai-proxy converts a Claude request with adaptive thinking and an output effort level to an Amazon Bedrock Converse request, it placed effort inside the thinking object. Bedrock expects thinking and output_config to be sibling fields in additionalModelRequestFields.

Ⅱ. Behavior

For a request containing:

{ "thinking": { "type": "adaptive" }, "output_config": { "effort": "high" } }

Before:

{ "thinking": { "type": "adaptive", "effort": "high" } }

(output_config lost, effort at wrong nesting level)

After:

{ "thinking": { "type": "adaptive" }, "output_config": { "effort": "high" } }

Ⅲ. Changes

• provider/bedrock.go — set output_config.effort as a sibling of thinking in additionalModelRequestFields instead of nesting effort inside thinking.
• provider/bedrock_thinking_test.go — updated the adaptive-effort test to assert the sibling structure (renamed ...IntoThinking → ...ToSiblingOutputConfig).

Ⅳ. Scope

Supported effort values remain low/medium/high; unsupported values are still omitted. Manual extended thinking (budget_tokens) and requests without adaptive thinking are unaffected — covered by the existing TestBedrockRequestDropsOutputEffortWithoutAdaptiveThinking and TestBedrockRequestDropsUnsupportedAdaptiveOutputEffort tests which continue to pass.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@afb72b8). Learn more about missing BASE report.
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4205   +/-   ##
=======================================
  Coverage        ?   69.25%           
=======================================
  Files           ?      170           
  Lines           ?    33773           
  Branches        ?        0           
=======================================
  Hits            ?    23390           
  Misses          ?     9539           
  Partials        ?      844           

Flag	Coverage Δ
wasm-go-plugin-ai-proxy	81.39% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ns/wasm-go/extensions/ai-proxy/provider/bedrock.go	68.76% <100.00%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.