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.

docs/references/shacraft-layout-verification.json

@@ -0,0 +1,16 @@
+{
+  "world": "shacraft_lobby_v2",
+  "source": "live Paper surface maps + bounded RPC water reads",
+  "verified_surface_columns": 589824,
+  "surface_mismatches": 0,
+  "unique_marker_blocks": 16967,
+  "planned_writes": 17040,
+  "original_water_columns": 42399,
+  "water_columns_obscured_by_markers": 932,
+  "water_obscured_by_markers_verified_intact": true,
+  "height_unchanged_columns": 587098,
+  "capture_started_at": "2026-09-13T01:03:10.136933937Z",
+  "capture_finished_at": "2026-09-13T01:05:10.066341053Z",
+  "atomic_snapshot": false,
+  "note": "World edits were idle during each capture. Terrain follows its original heights; raised markers represent future structures, not finished traversable paths."
+}