[Feature Request] Utility to compile and merge ASTM F3548-21 Annex A3 log files into KML #1759

Is your feature request related to a problem? Please describe.
When conducting multi-USS simulations (such as Operational Practicality "Day-in-the-Life" runs), interoperability evaluations, or post-flight airspace reviews, operators and service providers need a way to visually play back and review the 4D volumes that were planned and active in shared airspace over time.

Under ASTM F3548-21 (LOG0015, LOG0020, and LOG0035), USSs already log their operational intents locally and export them using the standardized Annex A3 common JSON export format. However, there is currently no standardized open-source utility in interuss/monitoring to convert one or more ASTM F3548-21 Annex A3 log exports into a consolidated KML playback file for visualization in tools like Google Earth.

Describe the solution you'd like
We would like a utility within interuss/monitoring that ingests one or more ASTM F3548-21 Annex A3 JSON log exports (from a single USS or multiple participating USSs) and compiles them into a single consolidated .kml (or .kmz) file.

Key capabilities we would like to see:

• Multi-Log Merging: Accept one or more Annex A3 JSON log files (e.g., exported from different USSs participating in a shared airspace simulation) and merge them into a single unified KML output.
• Operational Intent 4D Visualization: Render operational intent volumes (polygons and cylinders per LOG0015 / LOG0020 / LOG0035) as 3D extruded KML geometries (<Polygon> with altitude bounds) annotated with KML <TimeSpan> (<begin> and <end>) elements so volumes dynamically appear and disappear along the Google Earth timeline slider.
• Extensible Entity Support: Focus primarily on Operational Intents (4D volumes, states, and time spans), while allowing optional or future extensibility for other Annex A3 logged entities (such as Constraints or UA telemetry/positions) if present in the log files.
• Flexible Packaging: We are flexible on how and where this utility is packaged within interuss/monitoring (e.g., CLI entrypoint, Python module, or subpackage) to best fit the repository's existing structure and conventions.

Describe alternatives you've considered
Without a shared open-source tool in interuss/monitoring, individual USSs and operators would have to build and maintain bespoke, proprietary log-to-KML conversion scripts. This duplicates effort across the ecosystem, results in inconsistent KML representations, and makes it difficult to cleanly merge log exports from multiple USSs into a single joint playback visualization.

Additional context

• Standard References:
  • ASTM F3548-21 LOG0015 & LOG0020: Logging of operational intent details and updates.
  • ASTM F3548-21 LOG0035 & Annex A3: Standardized common data format (JSON schema) for exporting logged UTM data.
• Primary Use Case: Post-run playback and operator evaluation of shared airspace simulations (e.g., Operational Practicality assessments), where participating USSs export their local Annex A3 logs post-simulation and merge them into a single KML artifact for joint operator review.