chore: add project scaffolding, third-party assets and settings

- Terrain, Prefabs, Textures, Modelle (u. a. Lieferkarton-/Vibrations-
  Rohdaten in Assets/Data)
- Third-Party-Pakete: TextMesh Pro, Toby Fredson Foliage Engine, Sat
  Productions Street Lights, ProBuilder Data
- Neue Szene Boot.unity, Shop-Szenenordner
- Package-Manifest/Lock, ProjectSettings, Build-Profile, .slnx
- Doku: EDITOR_SETUP.md, INSTALL.md, TODO.md

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Assets/TextMesh Pro/Fonts/LiberationSans.ttf.meta

@@ -0,0 +1,19 @@
+fileFormatVersion: 2
+guid: e3265ab4bf004d28a9537516768c1c75
+timeCreated: 1484171297
+licenseType: Pro
+TrueTypeFontImporter:
+  serializedVersion: 2
+  fontSize: 16
+  forceTextureCase: -2
+  characterSpacing: 1
+  characterPadding: 0
+  includeFontData: 1
+  use2xBehaviour: 0
+  fontNames: []
+  fallbackFontReferences: []
+  customCharacters: 
+  fontRenderingMode: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: