[VSCode Extension] Unsupported content type: redacted_thinking when using OpenRouter

Bug Description

When using Claude Code VSCode extension with OpenRouter as the API provider,
the extension throws an error "Unsupported content type: redacted_thinking"
and the final text response is also lost (swallowed).

Environment

• Client: Claude Code VSCode Extension
• API Provider: OpenRouter (not direct Anthropic API)
• Model: Models with Extended Thinking enabled (e.g. claude-sonnet-4-6)

Steps to Reproduce

1. Configure Claude Code VSCode extension to use OpenRouter
2. Use a model that returns redacted_thinking content blocks
3. Send any message

Expected Behavior

• Either render the thinking content, or silently skip it and display the final text response

Actual Behavior

• Extension throws: Unsupported content type: redacted_thinking
• Final text response is also lost because stream processing aborts on the unknown content type

Additional Notes

• The CLI (terminal) version handles this correctly — no error occurs there
• Issue is specific to the VSCode extension's response rendering layer