fix(frontend): resolve yaml action inputs completions

[yassinedorbozgithub]

Screenshots

• After the fix

• Before the fix

Summary

This PR fixes YAML autocompletion for action inputs by correctly detecting the enclosing action when editing inside a task's inputs block. Completions are now resolved only for task-level action inputs and no longer incorrectly trigger within workflow-level inputs declarations.

Why

The previous detection logic could fail to identify the correct action context or confuse workflow-level and task-level inputs, resulting in missing or incorrect autocomplete suggestions. This improves the YAML editing experience and provides more accurate completions.

How to review

• Review the logic responsible for resolving the enclosing action from the current cursor position.
• Verify that completions are only shown inside a task's inputs block.
• Confirm that workflow-level inputs schema declarations are ignored.

Validation

• Verified autocompletion for multiple action types inside task inputs.
• Confirmed no completions are shown for workflow-level inputs.
• Tested nested tasks and different indentation levels to ensure the correct action context is resolved.

[yassinedorbozgithub]

Closed in favor of #2139