feat: make executor timeout configurable via server config

[NETIZEN-11]

Description

Fixes #6282

This PR makes the executor timeout configurable via server configuration instead of being hardcoded. Previously, the executor relied on a fixed DefaultExecutionTimeout, which limited flexibility across different environments (e.g., development, CI, production).

With this change, users can now control execution timeout behavior through configuration without modifying code.

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Changes

• Added ExecutionTimeout field to EventConfig (default: 5m)
• Propagated timeout value through config → service → executor handler
• Updated ExecutorEventHandler to use configurable timeout
• Implemented safe fallback to DefaultExecutionTimeout for invalid values (≤ 0)
• Added initialization logging for effective timeout value
• Updated service layer to inject configuration into handler
• Added comprehensive unit tests for timeout configuration and fallback behavior
• Updated example configuration and documentation

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Behavior

• If execution_timeout > 0 → use configured value
• If execution_timeout ≤ 0 or missing → fallback to DefaultExecutionTimeout

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Configuration Example

events:
  execution_timeout: 10m  # Custom timeout (default: 5m)

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Testing

• All existing tests pass

• Added TestNewExecutorEventHandler_TimeoutConfiguration

• Covered:

• Custom timeout usage

• Zero value fallback

• Negative value fallback

• No regressions observed

• Build and lint checks pass

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Notes

• Backward compatible (no breaking changes)
• Follows existing configuration patterns
• Minimal and clean implementation aligned with project structure

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Checklist

• Feature implemented as per proposal
• Acceptance criteria satisfied
• Tests added and passing
• Lint checks passing
• Documentation updated

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[CLAassistant]

All committers have signed the CLA.

[evankanderson]

Thanks for this. Could you coordinate with #6278 (and the comments there), since this seems to be a duplicate of that PR?

In particular, see the comment on #6278 (comment) about testing the timeout / cancellation behavior with a small requested timeout of e.g. 1-5 seconds, and a task which would try to execute for longer?

[evankanderson]

Hello @NETIZEN-11 -- are you likely to return to this PR?

[evankanderson]

I'm marking this PR as "request changes" (needs to integrate the cancellation testing from #6278) to help track which outstanding PRs need maintainer action vs contributor action.

[github-actions]

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