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>

server/resources/skills/recreate/SKILL.md

@@ -88,5 +88,5 @@ ask_user how to proceed. Do not start building before the user agrees.
   code are new. Facts needed for compatibility (file formats, constants, rules) are fine.
 - Original assets (graphics, sounds, levels) stay the user's files: the re-creation may load
   them from `original/` at runtime but does not copy them into the repository.
-- Use todo_write for the phases; delegate broad searches through decompiled output to
+- Report phases with craft_phase and use todo_write for the steps; delegate broad searches through decompiled output to
   explore subagents to keep your own context small.