docs: document mesh package and traced token viewer

docs/architecture.md

@@ -31,6 +31,7 @@ shared types/validation package.
 | `apps/proxy`       | Hono HTTP server: search + fetch endpoints  | Node         |
 | `packages/tts`     | Fetch save from Steam, BSON-parse to `TTSMod` | Node       |
 | `packages/extract` | Analyze a `TTSMod`: objects, refs, assets   | Isomorphic   |
+| `packages/mesh`    | 2D shapes + extrusion into 3D mesh geometry | Isomorphic   |
 | `packages/shared`  | Shared types + zod schemas                  | Isomorphic   |
 
 ## Dependency graph
@@ -40,6 +41,7 @@ apps/web ──► apps/proxy ──► packages/tts ──► packages/shared
       │            │            │
       │            │            └──► (fetchMod → TTSMod)
       │            ▼
+      ├──► packages/mesh ──► packages/shared (types)
       └──► packages/extract ──► packages/shared (types)
 ```
 
@@ -50,6 +52,8 @@ apps/web ──► apps/proxy ──► packages/tts ──► packages/shared
   (image → vector shape) over HTTP.
 - **`apps/web` → `packages/extract`** — uses `buildTree` / `collectRefs`
   to analyze a loaded `TTSMod` in the browser (tree sidebar + asset refs).
+- **`apps/web` → `packages/mesh`** — extrudes 2D shapes into 3D geometry for
+  the tile and token viewers.
 - **`apps/proxy` → `packages/tts`** — calls `fetchMod` / `getFileName` to serve
   item requests.
 - **`apps/proxy` → `packages/shared`** — uses shared types and zod schemas for