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>

config.example.toml

@@ -43,6 +43,9 @@ mcp_direct_limit = 15
 
 # Currency label for the cost statistics (prices below are in this currency).
 currency = "USD"
+# Largest file upload in MB. Uploads are sent in 8 MB chunks, so the reverse
+# proxy's body limit (e.g. Nginx client_max_body_size) does not apply.
+max_upload_mb = 500
 
 
 # -----------------------------------------------------------------------------