fix(bedrock): emit tool_call_end events for native tool streaming

[daniel-lxs]

Summary

Fixes #10328
Fixes ROO-311: Write to File truncates filenames at special characters before file content

Problem

The Bedrock provider was not emitting tool_call_end events after tool use streaming, unlike other providers (e.g., OpenAI, Anthropic). The NativeToolCallParser requires these events to finalize tool calls and flush complete arguments. Without them, the parser would continue accumulating arguments in a buffer that never got finalized, causing filenames with special characters like parentheses to get truncated.

Root Cause

Comparing to other providers like base-openai-compatible-provider.ts (lines 186-193), they explicitly emit tool_call_end events when the stream indicates tool calls are complete. Bedrock was missing this logic entirely.

Solution

• Add contentBlockStop event type to the StreamEvent interface
• Track tool call IDs when contentBlockStart receives a tool use block
• Emit tool_call_end when contentBlockStop is received for a tracked tool use block
• Emit tool_call_end as a fallback on messageStop with stopReason: tool_use for any remaining active tool calls

Testing

Added 4 new tests for native tool streaming support:

• Tests tool_call_end emission when contentBlockStop is received
• Tests tool_call_end emission via messageStop fallback when contentBlockStop is missing
• Tests multiple tool_call_end events for parallel tool calls
• Tests no tool_call_end when stopReason is not tool_use

All 58 bedrock.spec.ts tests pass ✅

[roomote]

Rooviewer   See task on Roo Cloud

Code review complete. No issues found.

The implementation correctly adds tool_call_end event emission for the Bedrock provider, consistent with other providers like OpenAI. The fix properly handles:

• Primary path via contentBlockStop events
• Fallback path via messageStop with stopReason: tool_use
• Multiple parallel tool calls
• Non-tool-use messages

Tests cover all key scenarios.

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