feat: Add legacy shaders, model I/O, and project panel functionality

- Introduced `legacy-shaders.js` containing vertex and fragment shaders for rendering.
- Implemented `model-io.js` for parsing and encoding GLB files, ensuring compatibility with glTF 2.0.
- Created `project-panel.js` to manage project resources and survey overlays, enhancing user interaction.
- Added `solar.js` for calculating solar positions based on UTC time, latitude, and longitude.
- Developed `three-renderer.js` as a standard backend for Three.js, managing scene rendering and material synchronization.
- Included a new GLB model `dum.glb` for testing and demonstration purposes.
- Established `data_checks.mjs` for validating model data and ensuring integrity of assets.
- Created `prepare_export.py` to facilitate Blender GLB exports, maintaining material and node references.
- Added `vendor_three.py` to download and configure a local version of Three.js for the project.

locenice/data/app-config.json

@@ -1,15 +0,0 @@
-{
-  "version": "locenice-web-01",
-  "model": "./models/dum.glb",
-  "renderer": "auto",
-  "threeModule": "https://cdn.jsdelivr.net/npm/three@0.180.0/build/three.module.js",
-  "threeLoader": "https://cdn.jsdelivr.net/npm/three@0.180.0/examples/jsm/loaders/GLTFLoader.js",
-  "cdnTimeoutMs": 6500,
-  "maxPixelRatio": 1.5,
-  "startAutoRotate": false,
-  "catalog": "./data/catalog.json",
-  "assets": "./data/assets.json",
-  "references": "./data/references.json",
-  "sceneMetadata": "./data/scene.json",
-  "site": "./data/site.json"
-}