docs: document iconify icons and object icon files

docs/implementation-plan.md

@@ -80,7 +80,10 @@ tts-workshop/
 │           ├── components/
 │           │   ├── SearchResults.tsx
 │           │   ├── ObjectTree.tsx     # containment-tree sidebar
-│           │   └── viewers.tsx        # viewer registry + default viewer
+│           │   ├── viewers.tsx        # viewer registry + default viewer
+│           │   ├── objectIcons.tsx    # class → icon mapping
+│           │   ├── objectIconsData.ts # generated icon subset (do not edit)
+│           │   └── objectIcons.test.ts
 │           └── stores/
 │               ├── searchStore.ts  # zustand
 │               └── modStore.ts     # zustand
@@ -204,10 +207,16 @@ proxy API and `packages/extract` directly for analysis.
   inspector pane for the selected object, and links to the raw save file.
 - `components/SearchResults.tsx` — result grid + pagination.
 - `components/ObjectTree.tsx` — recursive tree sidebar; each entry shows a
-  class tag + display label, indented by depth. Clicking selects an object.
+  class icon (hover for the class name) + display label, indented by depth.
+  Clicking selects an object.
 - `components/viewers.tsx` — viewer registry (`registerViewer` /
   `resolveViewer`) plus a `DefaultViewer` that renders an object's fields;
   custom per-class viewers can be registered later.
+- `components/objectIcons.tsx` — maps TTS object classes to one or more MDI
+  icons (`iconsForObject`); unknown classes fall back to a help icon.
+- `components/objectIconsData.ts` — generated by
+  `scripts/generate-object-icons.mjs`; registers only the used MDI icons with
+  Iconify's offline storage so the full set isn't bundled.
 - `stores/searchStore.ts` / `stores/modStore.ts` — Zustand stores for search
   and mod state.
 - `vite.config.ts` — dev proxy for `/search`, `/items`, `/health` →
@@ -248,6 +257,8 @@ packages/extract    →  flatten objects / extract refs / download assets
 - `cheerio` — Workshop browse page scraping (backend only).
 - `zod` — validation.
 - `react`, `react-dom`, `react-router-dom`, `zustand` — frontend.
+- `@iconify/react`, `@iconify-json/mdi`, `@iconify/utils` — iconify icons for
+  object class tags (subset bundled via `scripts/generate-object-icons.mjs`).
 - `vite`, `@vitejs/plugin-react`, `tailwindcss`, `@tailwindcss/vite` — frontend tooling.
 - `tsx`, `typescript`, `eslint`, `prettier` — tooling.