Refactor confusing 'm_filtered_log_event_map' naming to 'filtered_log_event_indices'

[coderabbitai]

Problem

The current naming convention using m_filtered_log_event_map is confusing because:

• The _map suffix typically indicates a hash map (std::unordered_map) or tree-based map
• The actual data structure appears to be a vector/array of indices, not a key-value mapping
• This naming pattern is used across both ffi-js and log viewer codebases

Proposed Solution

Rename m_filtered_log_event_map to filtered_log_event_indices (or similar) to better reflect that it contains a collection of indices rather than a mapping structure.

Context

This naming has been identified as confusing by multiple developers and would benefit from refactoring to improve code clarity and follow better naming conventions.

References

• Original discussion: feat: Add KQL query support for filtering structured IR log events. #104 (comment)
• Raised by: @LinZhihao-723 and @hoophalab

Impact

This is a cross-cutting refactoring that would require coordinated changes across:

• ffi-js codebase
• log viewer codebase

The change would improve code maintainability and reduce developer confusion.