Add Web Push, guided start screen, SVG icons, chunked uploads, rename

- Web Push (VAPID + RFC 8291, pure Rust): permission/question/finished
  notifications while no app window is visible; settings with test button
- Guided new-session flow: task, craft target (website/app/game/old
  software/fresh), clean room or deep, description, model, folder
  (new, existing or cloned git repository); originals upload to original/
- Craft phase bar (craft_phase tool) for study/specify/build/check/ready
- Chunked uploads (8 MB) up to server.max_upload_mb (default 500 MB)
- All UI glyphs and emojis replaced by themeable SVG icons
- Rename dialog with manual name or model-generated suggestion

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/vite.config.ts

@@ -31,6 +31,8 @@ export default defineConfig({
         runtimeCaching: [],
         // The STEP importer (OpenCascade, ~8 MB) is loaded only when needed.
         globIgnores: ["**/occt-import-js*"],
+        // Web Push handlers (push, notificationclick).
+        importScripts: ["push-sw.js"],
       },
     }),
   ],