fix: re-raise control-flow exceptions in ToolInterceptCapability.wrap_tool_execute

[Leoyzen]

Problem

The unified hook system refactor (fa326ff, PR #125) introduced ToolInterceptCapability.wrap_tool_execute() with a broad except Exception that swallowed all exceptions including control-flow ones:

• RunAbortedError — raised when user cancels elicitation/question (e.g. question_for_user cancel). Should propagate to NativeTurn.execute()'s except RunAbortedError handler to abort the run. Instead it was converted to a ToolReturn error response, causing the agent to continue executing after cancel.
• ModelRetry — pydantic-ai's retry signal for fixable tool errors. Should propagate to the pydantic-ai framework. Instead the LLM received it as a tool success with error text — semantically different behavior.
• ToolSkippedError — raised when a pre-tool hook denies execution. Should propagate as a skip signal. Instead converted to a tool error.

Evidence

From ~/Library/Logs/agentpool/acp.log:

[warning] Tool execution failed  error='User cancelled the questionnaire.' error_type=RunAbortedError tool_name=question_for_user

After the warning, the agent continued: CallToolsNode → ModelRequestNode (LLM got the error and generated another request).

Fix

Add except (RunAbortedError, ToolSkippedError, ModelRetry): raise before the generic except Exception block in wrap_tool_execute().

Tests

3 new regression tests in tests/agents/native_agent/test_tool_intercept_capability.py:

Test	Verifies
test_wrap_tool_execute_reraises_run_aborted_error	RunAbortedError is re-raised, not swallowed
test_wrap_tool_execute_reraises_model_retry	ModelRetry is re-raised, not swallowed
test_wrap_tool_execute_reraises_tool_skipped_error	ToolSkippedError is re-raised, not swallowed

Existing test_wrap_tool_execute_catches_exception (verifying normal ValueError is still caught) continues to pass. All 16 tests in the file pass, plus 11 question abort regression tests.

Affected Exception Sources

Exception	Raised by	Impact when swallowed
RunAbortedError	question_for_user.py:226, tool_impls/question/tool.py:103, agents/context.py:436	Agent continues after user cancel
ModelRetry	8 call sites across codemode, fsspec, subagent, question tools	LLM gets error text instead of retry signal
ToolSkippedError	mcp_server/tool_bridge.py:524	Skip signal becomes error response

[gemini-code-assist]

Code Review

This pull request ensures that control-flow exceptions (RunAbortedError, ToolSkippedError, and ModelRetry) raised during tool execution are re-raised and propagated rather than being swallowed as generic tool errors. Unit tests are added to verify this behavior. The reviewer suggests also propagating other critical control-flow exceptions, such as CallDeferred, ApprovalRequired, and ChainAbortedError, to prevent breaking deferred execution and approval flows.

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