feat(tabletop): add state, setup, mounting, and stacking

Implement the tabletop library's game state store, setup seeding with
bare-type expansion, surface mount tree resolution, part placement, and
the stacking positioning process with a dependency-free SVG path helper.
Wire the public API and add unit plus vite integration tests.

pnpm-lock.yaml

@@ -268,6 +268,9 @@ importers:
         specifier: ^5.0.14
         version: 5.0.14(@types/react@19.2.18)(react@19.2.8)(use-sync-external-store@1.6.0(react@19.2.8))
     devDependencies:
+      '@types/node':
+        specifier: ^22.12.0
+        version: 22.20.1
       '@types/react':
         specifier: ^19.2.18
         version: 19.2.18
@@ -277,6 +280,9 @@ importers:
       typescript:
         specifier: ^5.7.2
         version: 5.9.3
+      vite:
+        specifier: ^8.2.1
+        version: 8.2.1(@types/node@22.20.1)(esbuild@0.28.1)(jiti@2.7.0)(tsx@4.23.11)(yaml@2.9.0)
       vitest:
         specifier: ^4.1.10
         version: 4.1.10(@types/node@22.20.1)(vite@8.2.1(@types/node@22.20.1)(esbuild@0.28.1)(jiti@2.7.0)(tsx@4.23.11)(yaml@2.9.0))