Expand material support and checkpoint the completed building toolkit

Expose the runtime block/item registry through compact material search and
single-material descriptions. Preserve private block-entity data through
checked edits and durable undo without sending payloads to model context.

Include the completed terrain tools, isolated world/map plugin, station lift,
ACP streaming and guidance fixes, local camera auto-connect, construction
scripts, and their public documentation, references and verification records.
Active station decoration and private runtime data remain outside this commit.

Validation: 145 Maven tests, 47 Bridge tests, successful camera Gradle build,
and isolated Paper verification of all 1,196 block defaults plus 5,392
independent property cases for placement, same-material edits and restoration.

examples/terrain/small-hill.json

@@ -0,0 +1,39 @@
+{
+  "version": 1,
+  "min": {
+    "x": 0,
+    "y": 80,
+    "z": 0
+  },
+  "max": {
+    "x": 7,
+    "y": 87,
+    "z": 7
+  },
+  "base_height": 82,
+  "seed": 2809,
+  "mode": "sculpt",
+  "noise": {
+    "amplitude": 1,
+    "scale": 12
+  },
+  "palette": {
+    "rock": "minecraft:stone",
+    "soil": "minecraft:dirt",
+    "surface": "minecraft:grass_block",
+    "soil_depth": 3
+  },
+  "features": [
+    {
+      "type": "hill",
+      "center": {
+        "x": 4,
+        "z": 4
+      },
+      "radius": 1,
+      "height": 3,
+      "falloff": 3
+    }
+  ],
+  "preserve": []
+}