feat: application improvement

[drduhe]

Issue #, if available: n/a

Summary

Major refactoring pass to improve code organization, type safety, and maintainability across the Cesium globe application.

Changes

Project Structure & Tooling

• Renamed src/util/ to src/utils/ with more descriptive file names (smHelper → sagemakerHelper, mrHelper → modelRunnerHelper)
• Added Jest test infrastructure (jest.config.js, @types/jest, test/test:watch scripts)
• Added initial unit tests for cesiumFormatters, config, handleAwsError, logger, and shared types

Module Decomposition

• cesiumHelper.ts (722 LOC monolith → 4 focused modules):
  • cesiumFeatures.ts — GeoJSON loading & feature click handling
  • cesiumImagery.ts — Image/tile loading & Docker-based tile creation
  • cesiumFormatters.ts — Feature property formatting for popups
  • cesiumHelper.ts — Barrel re-export preserving existing import paths
• FormControls.tsx (506 LOC → 6 files):
  • DarkAutosuggest.tsx, DarkSelect.tsx, DarkMultiselect.tsx, DarkInput.tsx, DarkFormField.tsx, types.ts
  • FormControls.tsx becomes a barrel re-export for backward compatibility
• ExpandSection extracted from ImageRequestModal into its own component

New Custom Hooks

• useS3Browser — Shared S3 bucket/object browsing logic (replaces duplicated code in LoadImageModal, LoadDataModal, ImageRequestModal)
• useImageRequestResults — Auto-loads processing results on job success (extracted from ImageRequestModal)

Type Safety

• Added src/types.ts with shared types: ImageRequestState, ImageRequestData, ImageRequestOutput (discriminated union), ImageProcessor, FeatureDistillationConfig, PostProcessingStep
• Replaced any types across modal props, model runner interfaces, and status handlers with proper typed signatures
• Used strict equality (===) instead of loose (==) in output comparisons

Structured Logging

• Added src/utils/logger.ts with level-aware logging (debug/info/warn/error); suppresses debug in production
• Replaced all console.log/console.error calls with logger.* throughout the codebase

CSS & Design Tokens

• Introduced CSS custom properties for z-index layering (--z-vignette, --z-tray, --z-popup, --z-modal, --z-dropdown) and scrollbar styling
• Replaced hardcoded z-index values across all CSS files
• Fixed gap: 12 → gap: 12px bug in ImageRequestStatus.css

Imagery Pipeline Fix

• cesiumImagery.ts now warps images to EPSG:4326 via gdalwarp before tiling, correctly handling projected CRS and rotated rasters
• Added cleanupWarpedFile() for temp file cleanup
• calculate_extents.py updated to use the full GeoTransform formula (handles rotation via gt[2]/gt[4])

Config Centralization

• Extracted magic numbers into named constants: VIEWER_INIT_MAX_RETRIES, CAMERA_FLY_DURATION_SECONDS, POPUP_WIDTH, JOB_NAME_PREFIX, FALLBACK_DEV_URL, etc.

ResourceContext

• Fixed stale closure in zoomTo by using the state-setter pattern to read current resources
• Removed resources from the zoomTo dependency array

Checklist

Before you submit a pull request, please make sure you have the following:

• Code changes are compact and well-structured to facilitate easy review
• Changes are documented in the README.md and other relevant documentation pages
• PR title and description accurately reflect the changes and are detailed enough for historical tracking
• PR contains tests that cover all new code and the code has been manual tested
• All new dependencies are declared (if any), and no unnecessary libraries are added
• Performance impacts (if any) of the changes are evaluated and documented
• Security implications of the changes (if any) are reviewed and addressed
• I have read the Contributing Guidelines and agree to follow the Code of Conduct

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[devinglauner]

LGTM